The prosecution must prove that your driving ability was impaired at the time of driving due to the presence of an illegal substance.
Driving Whilst Impaired Through Drugs
The difficulty for the prosecution is establishing what level of drugs can be in a person’s system before they become impaired.
Expert Motoring Offences Solicitors
At GT Stewart Solicitors & Advocates, we understand that being charged with a motoring offence can be stressful, disruptive, and carry serious consequences. From speeding and driving without insurance to more serious allegations such as dangerous driving or driving under the influence, our specialist motoring offences team provides expert advice and representation at every stage of the process.
We guide our clients through police investigations, court proceedings, and potential licence or penalty issues, ensuring that all legal options are carefully considered. Our approach combines practical solutions with a strategic focus on protecting your driving record, liberty, and future.
Whether you are facing a single motoring charge or complex, multiple allegations, our solicitors act quickly to provide clear advice, robust representation, and support tailored to your circumstances.
Experienced Motoring Offences Lawyers
Our specialist motoring offences team has extensive experience representing clients facing a wide range of road traffic matters, from speeding, careless or dangerous driving, to more serious allegations such as driving under the influence or driving without insurance. We provide clear advice and representation at every stage, including police investigations, court proceedings, and licence-related matters.
We can help dramatically improve your chances of being found not guilty or avoiding disqualification. Email GT Stewart at roadtraffic@gtstewart.co.uk to speak with a member of our specialist motoring law team, or use our online enquiry form. We will respond at a time and date convenient to you, ensuring that you receive prompt, personalised advice tailored to your case.
Driving Whilst Impaired Through Drugs
Initially, the police will carry out a FIT test (Field Impairment Test) at the roadside to determine your level of impairment (if any). The officer carrying out the test must refer to standard guidelines and procedures for testing and will make observations in relation to the following:
- The size of your pupils (The Pupil Measure Test);
- Your balance and judgement (The Romberg Test);
- The Walk and Turn test;
- The one leg standard test; and
- The finger to nose test
If the officer decides that you have failed the test you will be required to provide a specimen of blood (or urine) at the police station. The police must offer you a sample of blood to take away with you from the police station. We would recommend that you arrange to have your sample tested as soon as possible. If you do not consent, you will be charged with an offence of failing to provide a specimen, unless you have a reasonable excuse such as a fear of needles.
It is not enough for the prosecution to prove that there was a drug present in your system, they must also prove that you were unfit through drugs. This is something that we are able to challenge on your behalf given the number of different factors which can influence the results of the FIT test. Contact GT Stewart at roadtraffic@gtstewart.co.uk in order to get urgent specialist legal advice.
Driving with Excess Drugs
The difficulties of successfully prosecuting a driver for driving whilst impaired through drugs forced new legislation to be introduced in 2015 by introducing specified legal limits for both legal and illegal drugs in order to measure an accepted level of usage before driving. The prosecution now have to establish that you were driving and the proportion of a specified drug measured in your blood is found to be over the prescribed limit.
The new legislation set limits for 17 ‘controlled drugs, some of which are used for widespread medicinal purposes (8) and those which are not with amphetamine being categorised separately.
| Controlled Drug | Limit (micrograms per litre of blood) |
|---|---|
| Benzoylecgonine | 50 |
| Clonazepam | 50 |
| Cocaine | 10 |
| Delta-9-Tetrahydrocannabinol (cannabis) | 2 |
| Diazepam | 550 |
| Flunitrazepam | 300 |
| Ketamine | 20 |
| Lorazepam | 100 |
| Lysergic Acid Diethylamide | 1 |
| Methadone | 500 |
| Methylamphetamine | 10 |
| 6-Monoacetylmorphine | 5 |
| Morphine | 80 |
| Oxazepam | 300 |
| Temazepam | 1000 |
| Amphetamine | 250 |
Our Services
At GT Stewart Solicitors, our specialist motoring offences team provides clear, practical advice across the full range of road traffic matters. Whether you are facing a speeding allegation, a drink or drug driving charge, or a more serious offence such as dangerous driving, early legal advice can make a significant difference to the outcome of your case.
We understand that for many clients, their driving licence is essential for work, family responsibilities, and day-to-day life. Allegations can carry penalty points, fines, disqualification, or even imprisonment. Our experienced lawyers will assess the evidence, advise you on your options, and build a strong defence where appropriate.
Below you will find guidance on the most common motoring offences we deal with, together with practical information about the legal process and how we can help protect your licence and your livelihood.
Click below to read detailed advice on each motoring offence.
Parking Fines and Offences
Why Choose GT Stewart?
“We will do all the law permits to keep you on the road”
GT Stewart have a proven track record of success with defending driving offences and know exactly how to prepare an effective defence in order to give you the best chance of winning your case.
Our Expert Lawyers are ready to Help
GT Stewart has established itself as a leading firm in the UK, specialising in both private cases and also Legal Aid work.
Meet some of our Motoring Offences team
Speak to one of our Motoring Offences Solicitors
Our Tenacity Results in Success
We represented a teenage client who was charged with murder, two counts of attempted murder, and possession of a firearm with intent to endanger life.
By | Jun 04, 2026
We represented an appellant whose conviction was referred to the Court of Appeal by the CCRC on the basis that there was no jurisdiction to hear one of the counts, as it involved alleged conduct committed outside the UK.
By | May 27, 2026
We represented a client in proceedings where the prosecution sought to invoke the “slip rule” under section 385 of the Sentencing Act 2020.
By | May 21, 2026
Client Testimonials
"Harry Charalambous and his dedicated team, Louise and Harry Pell, provided exceptional representation throughout my case, in which I faced a multitude of serious allegations. From the outset, they meticulously explained my options and guided me through every stage of the process. Their expertise and strategic approach ultimately led to my case being dropped before it even reached trial. During such a challenging and uncertain period, it would have been easy to lose hope. However, their unwavering commitment, support, and determination to prove my innocence gave me the confidence to keep fighting and persevere through one of the most difficult times in my life. What truly sets this team apart is their prompt communication, extensive knowledge, and carefully considered legal strategy, all of which contributed to achieving the best possible outcome. Harry Charalambous is a leading figure in criminal law, and I have no hesitation in recommending his services to anyone in need of expert legal representation. I am sincerely grateful for the hard work, dedication, and professionalism shown throughout my case. Thank you to the entire team for always being available to address my concerns and answer any questions I had along the way."
“I’ve worked with GT Stewart since 2014 in relation to matters involving my brother. Over that time, I’ve dealt mainly with Rebecca Hill and, more recently, Tahmina Islam. Having that continuity has been invaluable. They know my brother, they know our family and they understand the history of the case, which means we haven’t had to start from scratch every few years. I’ve always found them professional, passionate and easy to deal with. When I’ve needed advice or had concerns, they’ve been available and have taken the time to understand what matters to us. Acting as my brother’s litigation friend comes with a huge responsibility and I have always felt that he has been well represented. The fact that I’ve continued to return to GT Stewart over the last 12 years probably says more than anything else I could write. I trust them to do right by my brother.”
"Ghazala Parveen was thoroughly professional and very supportive throughout the process of our parole application. Her experience meant that a lot of the stress was taken away from us."
"I just wanted to say a huge thank you [Nick] for everything you have done for D and his case - I truly don’t think we would have had this outcome with anyone else. As soon as the case was with you it felt like a weight was lifted and all the things we were fighting for since the beginning came to light. D is doing so much better & hopefully things will only go up from here - myself and D's family are all so grateful for yours and Madeline’s work."
"You have been fantastic [Atia] - no issues whatsoever, fast responses, kept me up to date and handled every situation perfectly. Would/will use the firm for all future conveyancing. Thank you very much."