The government has dropped plans to ban poppers – just weeks before the law was set to come into force.

In January, Parliament voted to approve a blanket ‘legal highs’ ban that would prohibit the sale of drugs including alkyl nitrites (poppers), commonly used by gay men to help relax the anal sphincter muscles for anal sex.

Home Secretary Theresa May pushed through the legislation to make poppers illegal alongside substances such as nitrous oxide (laughing gas) – but conceded a review of the issue after expert recommendations and unrest among Tory MPs.

The law had been set to come into force on April 6 – but in a drastic last-minute intervention, the government this week intervened to ensure that the ban on poppers will not go into effect.

Home Office minister Karen Bradley confirmed in a letter to the Advisory Council on the Misuse of Drugs: “I understand that the Council has now advanced its understanding of the psychoactivity of the alkyl nitrites group under the Act and concluded that only substances that directly stimulate or depress the central nervous system are psychoactive under the Act.

“Having given due consideration, the Government agrees with your advice and interpretation of the definition.

“We do so in the understanding that “poppers” have these unique indirect effects. Our understanding is that this approach does not have any further implications for the operation of the Act and that other substances that the Act intends to cover are not affected.

“We remain confident that the psychoactivity of those substances can be established under the definition in the Act.

“We will ask law enforcement agencies to be guided by our agreement with your advice.

“Our acceptance of your advice brings to an end the review process we were undertaking in parallel to consider the case for a bespoke exemption for the alkyl nitrites group under the Act on the basis of their beneficial and relationship effects.

“The process to exempt substances from the Act applies only to substances which meet the Act’s definition.

She continued: “I am grateful for the ACMD’s updated assessment of the harms of “poppers”. This is in line with the government’s position that there are harms associated with this group of substances.

“Some formulations of ‘poppers’ have been banned under dangerous substances and cosmetic regulations.

“Your assessment of the harms of ‘poppers’ including the latest formulation isopropyl nitrite, will no doubt inform the regulatory authorities responsible for the General Products Safety Regulations 2005.

“We will ensure that our messaging across government and its agencies is updated.

“The ACMD advise that the reports of ocular damage though rare should be carefully monitored. Together with Government, I ask that the ACMD keep a check on this as well. “

The issue has been a cause célèbre of LGBT advocates in the Commons.

Conservative backbencher Crispin Blunt had outed himself as a user of poppers in a Parliamentary debate, while another, Michael Fabricant, also admitted to “trying” the drugs – though not for gay sex.

Mike Freer MP told PinkNews: “There was no evidence that poppers were psychoactive and now that has been officially confirmed, sense has prevailed.

“I am just disappointed that the Home Office didn’t listen to representations at the outset and this mess could have been avoided.

“Karen Bradley as the new Minister has been supportive and deserves credit for helping untangling the mess.”