Diane Abbott has described the war on drugs as a failure – but has ruled out Labour legalising cannabis.

The Shadow Home Secretary also revealed that a Jeremy Corbyn government would crack down on Bitcoin, which she called a “gigantic Ponzi scheme”.

Ms Abbott likened the threat posed by cryptocurrency to the failure of regulation which triggered the worldwide economic crash and recession a decade ago.

“If everyone took their Bitcoin money and tried to buy a new car all at once the whole thing would collapse,” she told Parliament’s House magazine.

And, asked if, Labour would introduce restraints, she added: “Labour overall thinks it’s important to have proper regulation of financial services.

“It was poor regulation of financial services which led to the 2008 crash and obviously regulating Bitcoin would be part of that.”

But Ms Abbott said: “It is not Labour’s policy to legalise cannabis for recreational purposes. We would not be discussing the legalising of cannabis for recreational purposes.”

However, she said Labour would expand drug treatment facilities as a better way to cut the numbers of addicts than the criminal justice system.

“What we all have to accept is that the war on drugs - particularly the international war on drugs - has failed,” Ms Abbott said.

“It’s turned countries like Colombia into narcotics paradises. And, far from the war on drugs succeeding in any way, what we have seen is a contributory stream of drug addiction with people in America being hooked on opiates and the consequences of being hooked on opiates is just as bad as heroin or cocaine or anything else and it’s cut a swathe of damage through middle America.”

She added: “We are not seeing, in this country, falling numbers of addicted people, so I think we do have to look at what we are doing and what’s working and what’s not working as the case may be.

“I certainly think we want to make it much easier for people to get treatment who are drug addicted.