Conservative opposition to government law and order crackdowns means the party is soft on crime, claimed Tony Blair on Wednesday.

During Commons exchanges, Iain Duncan Smith challenged the prime minister to come up with the number of criminals docked welfare benefits for breaching court orders.

"I can't," replied Blair to cheers from Tory MPs.

"The answer is just 39," responded the Conservative leader.

Proposals to hit the benefits of criminals had made the headlines in the run-up to local elections on May 2, but of 40,000 breached community sentences just 39 offenders had lost welfare payments, revealed Duncan Smith.

"Thirty nine and he said that, as he is fond of doing, that this scheme would make the criminals serve the sentences they were given."

Catching Blair on the back foot over figures, the Tory leader, combined an attack on police reforms, and Community Safety Officers, with a call for action not "gimmicks".

"It was just another gimmick. With violent crime rising doesn't he think instead of gimmicks it would be better to do what the public wants which is to put real police back on the streets not in their police stations."

But in a reversal of the traditional political divide on law and order, the prime minister took the Tories to task over their softness on moves to "toughen up" the criminal justice system.

"We're increasing the number of police officers, he opposed the investment necessary. We are saying that persistent offenders should not be bailed if on drugs, he opposed that measure too.

"We are saying that that if drug dealers, their proceeds of crime should be taken form them, they've opposed that measure too. We're saying there should be more Community Safety Officers to help the police, he's opposed to that measure too," said Blair, reeling off a litany of crime busting measures."

The message was clear, Conservative opposition to a raft of sweeping government measures - praised in liberal circles - ruled Duncan Smith's criticism out of court.

"I agree there is a real problem with street crime and violent crime," said Blair.

"The difference is yes there is a problem. We're dealing with, he's simply exploiting it."