Written by: Christopher Smith, PNLD Traffic Law Consultant
Not reviewed after the date of publication - 25 June 2026
In this article, PNLD’s Traffic Law Consultant Christopher Smith, examines how statutory powers, implied licence, trespass and bad faith interact in drink and drug driving investigations.
The cases referred to in this article are mainly citations of Road Traffic Reports, sourced from Wilkinson's Road Traffic Law 32nd Edition.
The power of entry previously provided under section 4(7) of the Road Traffic Act 1988 (RTA 1988) is now contained in section 17(1)(c)(iiia) of the Police and Criminal Evidence Act 1984 (PACE 1984), which provides a power of entry to arrest for the offence in section 4 of the RTA 1988.
Section 6E of the Road Traffic Act 1988 enables a constable to enter, if need be by force, any place either for the purpose of imposing upon a person a requirement for a preliminary test under section 6(5) or to arrest a person under section 6D, but only where there has been an accident in which the constable reasonably suspects that injury was involved. However, it is important to note that:
- There must have been an accident – it’s not enough for the constable reasonably suspect there has been an accident.
- The constable must reasonably believe (not suspect) the person was driving, attempting to drive or in charge of the vehicle at the time of the accident (see section 6(5)).
Outside the specific powers outlined above, officers have no specific power of entry for drink/drug driving investigations. PNLD Traffic Law Consultant Chris Smith examines the stated cases in this area, illustrating how the courts have considered and interpreted the law, alongside other associated matters such as cases where an accident has not taken place.
The RTA 1988 Act re-enacted and expanded the legislation and powers discussed in this article. Whilst the Road Traffic Act 1972 (RTA 1972) provisions discussed are no longer in force, the case law interpretation discussed throughout is still relevant when considering present day powers.
Police are trespassing
The case of Morris v Beardmore [1980] R.T.R. 321 established that a requirement to provide a breath test was not lawful if the officer was trespassing.
In this case, the police wanted to speak to a driver (B) who had been involved in an accident. They went to his house and were invited inside the premises by his son. B indicated via his son that he didn’t want to discuss the matter and that the officers should leave. The officers remained and went into a bedroom to require the driver to provide a specimen of breath for a breath test. B protested that the officers were trespassing and refused to take the breath test. He was arrested, taken to a police station, and ultimately charged with failing without reasonable excuse to provide specimens of breath for a breath test and of blood or urine for laboratory analysis, contrary to section 8(3) of the RTA 1972. The House of Lords ruled that, as the constable was a trespasser, the driver’s detention or arrest following his refusal to give a breath test was unlawful.
In Clowser v Chaplin; Finnigan v Sandiford [1981] R.T.R. 317, police officers wanted to speak to a driver in connection with an accident. At C’s house his wife told them they must not enter and must wait outside. C came to the door and was required twice to take a breath test – he refused. He began to go back inside the house so one of the officers took hold of him and told him he was under arrest for his refusal. A struggle took place, but C was eventually taken to the police station and charged with failing to provide a specimen of breath for a breath test. In Finnigan v Sandiford, S was arrested at his home in similar circumstances. The House of Lords unanimously held that the constables effecting the arrests being trespassers at the time had no authority to arrest under section 8(5) of the RTA 1972, the law in force at the time.
Driver locked himself in his car
In Pamplin v Fraser (No.1) [1981] R.T.R. 494, two uniformed police officers saw a vehicle with a lighting defect. They followed the vehicle and because of the person’s manner of driving, suspected the driver (P) had consumed alcohol. P drove off the road into an alleyway that was on his own property – the officers followed him. P subsequently wound up all vehicle windows and locked himself inside, he didn’t inform the officers they were on his private land. One of the officers required P to provide a specimen of breath for a breath test, the driver replied, ‘You’re not getting a test off me. I won't let you in my car. I can stay here for ever if necessary.’ The officers told P he was under arrest and called for assistance. Approximately 20 minutes later the car door was opened, and P was taken to the police station. At court he was convicted of failing to provide a breath specimen (contrary to section 8(3) of the RTA 1972) and wilful obstruction (contrary to section 51(3) of the Police Act 1964 in force at the time). On appeal, the Divisional Court ruled that:
- The constables had an implied licence to enter which was not withdrawn so that the arrest and requirement to give breath was lawful.
- The constable was entitled to arrest him under section 8(5) of the 1972 Act and P had wilfully obstructed the constable in the execution of his duty.
After the cases outlined above, the implementation of the Transport Act 1981 made changes to the RTA 1972, which from 1983 gave police officers a power of entry (by force if necessary) to require a person to provide a specimen, where there had been an accident involving injury to another person, or to arrest a person who had failed to provide a specimen.
Does an unlawful arrest affect evidence from specimens taken at a police station?
In 1985, there then followed the case of R v Fox [1985] R.T.R. 337. A driver (F), with a passenger, was involved in an accident and left the scene – no other person or vehicle was involved. Police went straight to F’s home (they had no information about the physical condition of F or his passenger i.e. no reason to suspect injury) and knocked on the door. They received no response but could hear voices inside so they entered (without permission). They found F and required him to take a breath test, but he refused and so the police arrested him and took him to the police station, where he was found to be over the prescribed limit. He was convicted by justices of failing to supply a specimen of breath and driving with a breath-alcohol level above the prescribed limit. On appeal to the Divisional Court the conviction for failing to supply a specimen was quashed, but the conviction for being over the prescribed limit was upheld. F appealed to the House of Lords – dismissing the appeal, they ruled that under the substituted provisions:
- Evidence of a specimen of breath obtained at a police station in accordance with the procedure laid down in the Act and without any trick or impropriety (bad faith) was admissible even though F had been unlawfully arrested.
- Whilst the police had been trespassers and F’s arrest had been unlawful, the evidence obtained was admissible subject to the court's discretion to exclude it if obtained oppressively or by a trick.
Conclusively, a lawful arrest was not an essential prerequisite of a breath test, and there was no general principle that there couldn’t be a conviction under section 6(1) (driving, or being in charge, with blood-alcohol concentration above the prescribed limit) of the 1972 Act if the evidence by which it was sought to prove the offence had been obtained unlawfully.
Can police officers go onto someone’s property?
In Snook v Mannion [1982] R.T.R. 321, two police officers in a patrol car saw a car being driven erratically and followed it keeping it in sight all the time until it stopped in the driver’s driveway. The driver S got out and threw his keys into a flower bed. The officers walked onto the driveway; told S they suspected he had alcohol in his body and required him to provide a specimen of breath for a breath test – he refused. A second requirement was made to which the driver replied, “fuck off.” The officers arrested him and took him to the police station, where he provided a blood sample of 201 milligrams of alcohol in 100 millilitres of blood. S contended that by his words he had requested the police officers to leave his driveway so that their continued presence there was illegal and his arrest was unlawful. On appeal to the Divisional Court, the appeal was dismissed, they held that:
- in the absence of a locked gate or a notice such as ‘police keep out,’ police officers, like all citizens, had an implied licence to proceed from the gate to a front or back door of a house if they had legitimate business with the occupier; and
- it was for the justices to decide whether the licence had been terminated in all the circumstances – in this case the justices concluded that the driver’s vulgarity was insufficient to revoke the licence.
However, in Matto v Wolverhampton Crown Court [1987] R.T.R. 337, two police officers in a marked vehicle saw a red Ferrari Boxer, which they thought was exceeding the speed limit. Owing to traffic conditions, they didn’t catch up with vehicle for over a mile and when they overtook to stop it, M suddenly attempted to turn left into a driveway and in doing so lost control of the vehicle and skidded to a stop. M then reversed before continuing up the driveway to his mansion property. The police officers followed the Farrari approximately 200-300 yards up the driveway to where it had stopped. One of the officers approached M, the driver, who was still in his vehicle, and said “due to the way in which you've been driving and because you've exceeded the speed limit, I require you to take a breath test. If you fail or refuse to do so you may be arrested”, to which the driver replied, “this is private property: you can't do this.” His eyes were glazed and he smelt of intoxicants. The other officer said, “will you take the test.” M replied, “you can’t do this.” The Crown Court were satisfied that at this point the officers both knew their implied licence to enter the property had been terminated. M hadn’t used the word ‘trespassers’ but what he said clearly indicated to the officers that that was their position. The officer continued saying “we know what we are doing: if I wrongfully arrest you, you can sue me ok?” M replied – “ok.” He provided a positive screening breath test, was arrested and taken to the police station where analysis showed he had 73 microgrammes of alcohol per 100ml of breath. M was convicted of driving whilst over the prescribed limit.
The driver appealed to Crown Court, this was dismissed on the basis that, whilst the officers knew they were acting outside their powers (therefore mala fides), M had provided the screening breath test voluntarily.
M appealed to the Divisional Court, which was allowed, they held –
- The wrong approach had been adopted by the Crown Court.
- The Crown Court’s finding that the officers had acted mala fides (essentially in bad faith) was inconsistent with the finding that the breath sample had been given voluntarily.
- Given the finding of mala fides by the Crown Court, that court could or might, have used its discretion under section 78 of the Police and Criminal Evidence Act 1984, to exclude evidence of the breath-alcohol analysis.
The appeal was allowed.
Police officer’s conduct – discretion to exclude the evidence under section 78
In Sharpe v DPP [1993] R.T.R. 392, two police officers saw a van drive on the wrong side of the road and cause an oncoming car to brake hard. The van driver was also seen to cross the centre line of the road several times and on entering the close where he lived, he narrowly avoided colliding with a parked car. The officers had been following the van with their lights and sirens activated. The driver, S, got out of the van and staggered onto his driveway, followed by one of the police officers – the officer could smell intoxicating liquor on his breath and observed slurred speech. S made it clear to the officers that their presence on his property was unwelcome and that they were trespassers. He was led/dragged down his pathway back to the road, where he was required take a breath test – this he failed to do. S was arrested and taken to the police station where he was found to be over the prescribed limit, with a lower reading of 111µg/100ml of breath.
At trial the police officers accepted they had been told they were trespassers and at the end of the prosecution’s case, S applied for witness summonses for two of his neighbours, so they could give evidence of the police officer’s oppressive behaviour and of his normal driving in the close. This was so that the justices could consider exercising their discretion to exclude the evidence of the breath analysis under section 78 of PACE 1984. The justices refused to do this because the officers accepted they were trespassing and as they had already provided adequate evidence of S’ bad driving prior to entering the close, the neighbour’s evidence would add little. S was convicted and appealed.
Allowing the van driver’s appeal, the Divisional Court held that –
- The conduct of the constables in stopping and arresting S in his driveway was relevant to the justices' exercise of discretion under section 78.
- The justices had not exercised their discretion, for they had in fact stated that, whatever the witnesses might have said and however bad the constables' behaviour might have been in the S’ driveway, the justices would still not have excluded the breath analysis evidence.
- Therefore, the justices had made a mistake in excluding the witness evidence.
Interestingly, during the case, it was submitted on behalf of S that where mala fides (bad faith) was established, the discretion under section 78 could only be exercised in one way i.e. to exclude the evidence of the breath analysis but this was not accepted by the court.
Summary
Other than the current specific powers of entry under section 6E RTA 1988 (in the case of accident) or in relation to section 4 (impairment – entry to arrest under section 17 PACE 1984), there aren’t any other specific powers of entry onto someone’s private property for drink/drug drive offences. If someone tells a police officer they are trespassing and must leave etc., any subsequent arrest for failing to co-operate with a preliminary test would be unlawful and so any prosecution for failing to provide wouldn’t succeed. However, it wouldn’t affect evidential testing at a police station unless there are grounds to consider section 78 PACE 1984 and if there where such grounds, the case law indicates that the courts are generally tolerant of a genuine mistake made by a police officer but they are however intolerant of bad faith on the part of the police.
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