Dope-smoking Conservative ministers have been accused of hypocrisy by North Norfolk MP Norman Lamb.

Mr Lamb, who put forward a bill to legalise cannabis in the House of Commons on Wednesday, said ministers who had themselves taken drugs were content to criminalise citizens and put them at risk from criminals selling dangerous drugs.

He turned his fire on prime minister David Cameron who in opposition backed radical reform of drugs laws, and repeatedly refused to answer questions during his successful Tory leadership campaign on whether or not he had taken drugs, hinting he had taken drugs by saying he had had a 'normal' university life.

'How many members of this government have smoked cannabis whilst maintaining their support for the conviction of their fellow citizens?' he asked.

'The prime minister was a reformer, it was also reported that he and others were caught smoking cannabis at Eton. He has gone on to do quite quite well,' he said.

He said there was a 'new rational approach emerging'.

'The public has moved on a lot from where the politicians are at on this. It is the sort of thing where politicians are afraid to say what they believe or to be brave about it and I think we have got to get this debate into the open and reach a more rational conclusion.'

The North Norfolk Liberal Democrat said he was hostile to drugs and had never taken illicit drugs himself.

But said: 'I think it is a bizarre position we have got ourselves into where we hand over the supply of potentially dangerous products to organised crime.

'Organised crime makes billions of pounds each year from the sale of cannabis. The crazy thing is anyone who wants to buy cannabis, you have no idea what they are buying. People end up buying skunk because they have no idea what potency they are buying. It is so much more sensible to control what you are doing. If you get the percentage right you can limit the danger as well.'

He also said the legalisation could see billions of pounds taken away from criminals and tax revenues could be used for good things like policing, education and health. 'Critically we free up police time to focus on violent crime and other serious offences and would also end the crazy criminalisation of people which blights their careers.'

Mr Lamb's Cannabis (Legalisation and Regulation) Bill is supported by a selection of Green, Labour and Tory MPs.

It was adopted by the House unopposed and its second reading has been set for April 22.

However, the Bill is unlikely to become law without the backing of the Government.