If you have been charged with driving while under the influence of drugs you will want to know what happens next and whether you can get off. On average, four UK motorists are found guilty of drug driving every day. Getting the right advice from an experienced criminal lawyer can make all the difference between a lengthy driving ban or criminal record and receiving a less severe penalty.

What does the law say?

In 2015 the drug driving law changed to make it easier for the police to catch and convict drug drivers. In a nutshell, it is illegal to drive if you are unfit to do so because you are on illegal, or legal drugs, or when you have a certain level of illegal drugs in your blood stream. Section 4 and section 5A of the Road Traffic Act 1988 set out the relevant law. A conviction for drug driving will appear on your criminal record.

The law gives police the powers to test and arrest any motorist they suspect to be under the influence of drugs. Police officers can test for certain drugs at the roadside and other types of drugs back at the police station. Even if you have passed the roadside test, you can be arrested if police consider your driving is impaired by drugs.

Zero Tolerance

It is now a criminal offence to drive with any of 17 drugs in your bloodstream above a specified level. The limit for each drug is different but the limit is set very low for illegal drugs. The government has taken a zero-tolerance approach to eight drugs most associated with illegal use, including cannabis, heroin, cocaine, LSD, and ecstasy.

Prescription medications

Prescription or over the counter medications are considered to be legal drugs. Medicinal drugs include morphine, codeine, and methadone. Provided you have been prescribed these drugs by a healthcare professional, have taken them as directed, and they have not affected your driving, there should be no problem. However, it is illegal to drive in England, Wales, and Scotland if your driving is impaired because of having taken legal drugs. Therefore, for at least any of the following drugs it is worth talking to a healthcare professional about whether or not you should drive:

  • amphetamine, for example dexamphetamine or selegiline
  • clonazepam
  • diazepam
  • flunitrazepam
  • lorazepam
  • methadone
  • morphine or opiate and opioid-based drugs, for example codeine, tramadol or fentanyl
  • oxazepam
  • temazepam

If you are taking any of these “controlled drugs” on prescription, it is a good idea to keep the prescription with you as evidence, in case you are stopped by the police.


Drug driving is considered a serious offence with strict penalties. The penalty you receive will depend on what you have been charged with. It is up to the magistrate who hears the case at the local court to decide which is most appropriate in your circumstances. The strictest penalty is likely to be an unlimited fine and/or six months imprisonment and a driving ban for a minimum of a year. Your driving licence will show that you have been convicted of drug driving and this will remain on the licence for 11 years. The maximum penalty for causing death by careless driving under the influence of drugs is life imprisonment.

Sentences depend on which drug and how much of it is found in the body from testing. The court will then adjust the amount depending on a variety of mitigating or aggravating factors.

This means it is very important if you intend to defend your position to seek expert legal advice to help prepare your defence.

Accidental exposure and other defences

Each case is different, and your best defence is going to depend on the particular circumstances. It is worth noting however that it may be possible to avoid conviction if the offence cannot be proved to have been committed.

If someone added an illegal substance to your drink without your knowledge, you may have been accidentally exposed to the drug and it may be possible to avoid a driving ban and criminal record.

As a general rule, the law may not apply on private land such as a private road, carpark, university or school campus. Other defences including driving while under the influence because of an emergency situation such as getting someone medical help or hospitalisation or ensuring personal safety. A high number of successfully defended cases depend on failure by the police to follow correct procedure during the arrest and testing.


A conviction for drug driving can have many negative consequences. You may lose your job or clients, if you are in business. Your vehicle insurance premiums will increase, and you may have difficulty obtaining travel visas or renting vehicles in countries such as the United States. There are however defences that can be used to your advantage. Understanding the court process and having a lawyer coach you before your hearing will give you the best possible chance of avoiding a criminal record, a hefty fine, or driving ban.

This is general information only and you should obtain professional advice relevant to your circumstances. If you or someone you know wants more information or needs help or advice, please call 0151 239 1020 or email [email protected].