A former UK Health Secretary has claimed “probably half the Cabinet” have used cannabis as Home Secretary Sajid Javid rejected calls for the legalisation of the class B drug but ordered a review into its medicinal use.

Norman Lamb, the Liberal Democrat MP, called for the complete legalisation of cannabis, saying current Government policy was a "dreadful hypocrisy".

He echoed a call from Lord Hague, the former Tory leader, to bring in a regulated market for the drug.

The Norfolk MP said: "Probably most of the Cabinet drink alcohol, the most dangerous drug of all, probably half of the Cabinet have used cannabis, possibly even the Home Secretary, unless they're a group of very odd people.

"Shouldn't the Home Secretary actually follow the advice of the former Conservative leader Lord Hague, who makes the case for a regulated legalised market, and that that is the best way to protect people from harm who at the moment buy from criminals who have no interest in their welfare at all?" asked Mr Lamb.

But Mr Javid, during a Commons statement to announce the Government review on the medicinal use of cannabis, said it was about making sure the country had the “best possible medical treatment available for everyone in the UK but especially our children”; it was not, he insisted, about the recreational use of drugs, which “can cause severe damage to people”.

Later, Theresa May’s spokesman was asked if the Prime Minister had ever smoked cannabis, to which he replied: "No."

The Government review comes in the wake of a series of appeals from parents, who want their children to be able to access medications, which can alleviate epilepsy and other illnesses.

Mr Javid explained how he had authorised the issuing of a licence on Tuesday for six-year-old Alfie Dingley, after his mother said she had been waiting three months for Mrs May to fulfil a personal assurance that he would be allowed to receive cannabis oil.

He told MPs the review would be held in two parts. The first, led by chief medical officer Sally Davies, would make recommendations on which cannabis-based medicines might offer patients real medical and therapeutic benefits.

The second would be considered by the Advisory Council on the Misuse of Drugs to see whether changes should be made to the classification of such products on an assessment of "the balance of harms and public health needs".

The Home Secretary said: "If the review identifies significant medical benefits, then we do intend to reschedule. We have seen in recent months that there is a pressing need to allow those who might benefit from cannabis-based medicines to access them."

Hannah Deacon, Alfie's mother, said she had been "overwhelmed" by Mr Javid’s announcement and voiced hope it would be easier to access to get cannabis medication in the future, saying it would be "madness" for sufferers to miss out.

She said she also wanted the Government to make it easier to do research into the medical properties of the plant, saying: "Hopefully, we will have a more forward-thinking way of doing things in this country and medicinal cannabis will hopefully, in five or 10 years’ time, be the norm.

"That is what I would want, because I would not want any other child to go through what my son has," she added.

The announcement of the review came just days after the Secretary of State intervened to permit the use of cannabis oil to treat severely epileptic 12-year-old Billy Caldwell, who had been admitted to hospital with seizures after supplies his mother had brought from Canada were confiscated at Heathrow.

Billy's mother Charlotte described the Government review as "amazing news".

Following the Commons exchanges, Sir Desmond Swayne, the former Conservative Minister, asked: "Where is everybody? I hope in the light of the extraordinary accusations of [Mr Lamb], they are not behind the bike sheds having a spliff."

Speaker John Bercow replied: "That is a most unworthy thought," and added: "He errs on the side of pessimism in his assessment of the character of his colleagues."