The former deputy Prime Minister Nick Clegg has urged the government to allow the manufacture of poppers to continue while a review of the recreational drug takes place.

Poppers – or alkyl nitrates – are due to become illegal in the UK when the Government’s new Psychoactive Substances Bill is implemented on 6 April, banning so-called “legal highs”.

The Bill will apply a blanket ban to any substance that produces “a psychotic effect”, including Nitrous Oxide or “laughing gas”.

A host of exemptions have had to be included for products such as alcohol, tobacco, coffee, tea, food and other medicinal products.

A review of the ban is due to take place after many MPs criticised the bill in January and urged that poppers be removed from the legislation.

Britain is the largest market for poppers in the EU

The findings of the review are due to be reported before the summer recess in July, leaving a three month gap in which UK poppers manufacturers may be put at risk.

Mr Clegg is leading a campaign urging EU leaders to back a reform of drugs laws.

He told the Guardian: “Poppers have been around for decades. “The evidence shows they don’t pose any risk to health, and that’s why they’ve never been banned before.

“While there is a review on going, of course the legitimate business that produce poppers should be allowed to continue to operate.”

Britain is the largest market for poppers in the EU with 670,000 people aged 15 to 24 experimenting with them, according to a study by the UN Office on Drugs and Crime in 2013.

The largest manufactures in Europe are located in Yorkshire, with major factories located in Huddersfield and Leeds. The two northern companies sold 2 million 10ml bottles of the drug last year, the Guardian reports.

The plan to outlaw poppers is part of a piece of legislation aimed at countering the rise of designer drugs blamed for 60 deaths in 2013 in England and Wales, according to a new report by the Home Affairs select committee.

However, many have taken Mr Clegg's line and called for poppers to be removed from the Bill. In January, Conservative MP Crispin Blunt said he used Poppers and described the ban as “manifestly stupid”.

Poppers’, physical effects, which include a short-live high and the loosening of muscles, have been known to improve anal sex and the drugs are used chiefly, although not solely, by gay men.