According to the law, a roadside drug test is called a “preliminary” test. To check for the presence of cocaine or cannabis, a swab is used to collect a sample of saliva from within the mouth. Police may ask you to submit to a field impairment test or give a blood sample at the police station if they suspect you of using drugs of any kind, even if you pass a roadside drug test. If the authorities have a valid cause for requesting a roadside drug test, you cannot deny it. It is a crime to do this.
Only if you have a valid reason can you decline a roadside drug test. There are very few valid reasons to decline a roadside preliminary drug test. To some extent, this can be explained by the fact that, compared to other test instruments, like the drawing of blood, which requires a needle and syringe, the saliva tests are much less intrusive. In case you cannot fulfill the request to undergo a drug test on medical grounds, then you might be excused.
Legal grounds for police drug testing
Officers must follow a certain set of guidelines in order for a police drug test to be legal and for the results to be reliable. These guarantee that the test is administered equitably and that your rights are respected:
- The purpose of the stop and the police officer’s plan to provide a drug test must be communicated properly. Your rights should be explained to you, along with the repercussions of declining the test.
- To determine whether you are impaired, a preliminary impairment test is typically conducted as the initial stage. This test may involve eye and balance tests. The police may test saliva for drugs, including cocaine and cannabis, using a roadside drug screening device if they suspect drug usage.
- You can face drug-related driving charges if the station’s final test results in a positive result. The allegations against you and your future rights must be explained by the police.
What counts as a failed drug test?
- After failing a drug test, it is only natural to feel that you are powerless about the situation. Nevertheless, it is essential to be capable of providing a situational explanation of such findings, both when you have consumed not only legal but also illegal drugs, or when you believe that the result could be the outcome of an error made during the procedure.
- You can also have a positive result in case you have been prescribed certain drugs that you have to take according to the prescriptions. You can justify your reason for taking these drugs easily by providing a prescription or a letter from a doctor, and this can be used to defend yourself.
- When you get in contact with secondhand marijuana smoke, there may be traces of the drug in your blood.
- Your solicitor may contest a positive result if it is the result of testing faults, defective equipment, incorrect sample handling, or a failure to follow proper testing protocols at the police station or at the roadside.
- “Residual traces” is the term for certain drugs, including cannabis, that can remain in your system for weeks.
Your rights if you’re asked to take a drug test
You are free to demand that the officer explain why he or she believes a drug test is necessary. They should provide an effective, lawful explanation that is backed by observable facts or situations. Note, however, that in case this results in the delay of the process, it will not be accepted by the police. A lawyer will be able to help you with your rights and the most appropriate course of action at once. It is important to remain calm and cooperative even when you demand your rights.
It might be harder as I am confrontational. Moreover, you are to understand that the inability to provide a specimen or a refusal to do it might lead to an additional fee. Record the time, location, officers, and reasons, as far as possible, as to why the test was conducted. If you later need to contest the operation, this information can be crucial. Whatever the test’s result, get in touch with a lawyer right away if you think it was performed without the required justification. They can assist you in contesting the validity of the test as well as any possible charges.
Consequences of refusing a drug test
England and Wales now have a “zero tolerance” policy for drug-related driving. As a result, you should anticipate being arrested and having to provide a blood sample at the police station if you fail a roadside drug test. You will be prosecuted, usually through a postal demand, and you will have to appear in court if your blood is found to contain more than the allowed amount of any restricted substance. The seriousness of your offense will determine the sentence you receive if found guilty. The following are some of the choices that a court may consider:
- A 12-month minimum driving prohibition
- An indefinite fine
- A community order consisting of unpaid labor, a curfew, and/or rehabilitation requirements
- A six-month jail term
Police powers under the Misuse of Drugs Act 1971
Strict laws and regulations control police drug testing in order to strike a balance between individual rights and public safety. A number of subsidiary laws supplement the main laws, which include the Misuse of Drugs Act of 1971 and the Road Traffic Act of 1988. These statutes give police the right to administer drug testing under certain conditions.
The following are justifications for police to seek a drug test:
- In case a police officer suspects that you are driving a vehicle under the influence of drugs, he has the right to pull you over and perform a roadside drug test. It is often based on the observable signs of unstable driving, incoherent speech, or the heavy smell of drugs.
- To eliminate the possibility of impairment as a factor in a traffic crash, the police can request you to provide a drug test.
- Drug testing may be requested by a police officer during their investigation following the arrest for certain crimes, especially those that seem to involve the use of drugs.
Drug wiping and screening equipment
Roadside drug tests, in England and Wales, are used to detect the remains of cocaine and cannabis. You will be taken to the police station, where a blood sample will be demanded in case the outcome of your saliva swab turns out positive. The blood sample is going to be tested for 17 limited substances that are restricted legally.
The laws in the United Kingdom define the circumstances under which police officers are allowed to carry out roadside drug tests. Being aware of your rights in the case is vital since the possibility of denying a drug test due to a lack of knowledge of whether or not it suits you or not would have significant legal consequences should you be convicted of drug driving in the future.
Role of consent and reasonable suspicion
There are still regulations that must be adhered to, even when there is a legitimate and obvious need for a drug test in the workplace. This entails getting each person’s written consent before testing them for drugs and getting separate written consent before testing them for alcohol. In certain situations, consent can have previously been acquired through a collective bargaining agreement. The most common form of drug and alcohol testing is automatic testing, especially in industries such as transportation and construction, where the safety of the worker is vital to their employment.
This can also be provided by the employment contract of an employee, whereby, before the employee is taken on board, a specific provision is provided, or as part of a combined policy of workplace health and safety. This will therefore serve as the foundation for the employee’s prior consent to be tested either randomly or regularly. Regardless of whether an employee works in a safety-critical section of your company and testing is necessary because of their job, you must nevertheless get their written consent before conducting a drug test in the absence of any previous contractual agreement.
Impact of drug testing on employment and driving
The process of the results of your blood test being returned in the UK takes, on average, six to eight weeks. This period is not fixed in stone, however, and the waiting period is customary and has to be much longer before the results will be given. Your drug test results may take longer than expected due to several reasons, most of which you have no control over. These consist of:
- The lab might not have enough employees.
- A backlog of samples could exist.
- It’s possible that the police station procedure went more slowly than usual.
Case studies and recent legal developments
The UK’s growing police powers and scrutiny of testing procedures are reflected in case studies and recent legal developments about police drug testing. The Crime and Policing Bill 2025, which expands police’s authority to test for drugs in custody from class A to all specified banned substances, including classes B and C (such as cannabis), is a significant legal change. With some prior offenses eliminated where drug connections are no longer obvious, this expansion also expands the list of trigger offenses that need drug testing, including violent crimes connected to drug usage.
Regarding case studies, a major, far-reaching examination discovered that a wide range of drug-testing outcomes in forensic science firms had been tampered with, and therefore a considerable number of samples, as well as over 40 drivers that were convicted of driving offenses, were retested and acquitted.
An officer of the police should possess a reasonable reason as to why you can be suspected of driving under the influence of drugs. Police may request a roadside drug test in case of a dangerous or erratic driver, an accident that has occurred, or signs of drug use, such as slurred speech or enlarged pupils. Drug-driving in the UK is highly illegal, and the conviction results in a one-year minimum driving ban. The other fines are normally a jail sentence, or an unlimited penalty (or both). Additionally, you will have a criminal history.
