Retailers caught selling nitrous oxide could face up to 14 years in prison, as the government is to class the substance as a class C illegal drug by the end of the year.

Under the Misuse of Drugs Act, production of the substance, also known as laughing gas, will also be prohibited. There will be exemptions for legitimate uses of it, such as for use as a medicine or for catering.

Plans to ban the gas were initially announced in March as a way of tackling antisocial behaviour. It is popular among 16-to- 24-year-olds, who release the substance from small silver canisters into balloons for inhalation.

Home secretary Suella Braverman said: “The British people are fed up with yobs abusing drugs in public spaces and leaving behind a disgraceful mess for others to clean up.”