Media playback is unsupported on your device Media caption David Cameron says the criminal justice system "sends too many of the wrong signals''

The maximum amount that people on benefit can have docked to pay fines will increase to £25 a week, the government has said.

PM David Cameron said the measure was being introduced as a deterrent, adding that the current system was "too soft".

At the moment, benefit claimants who receive fines can have £5 a week deducted from their income.

Labour said it supported moves to make people "pay for their crimes whether they're on benefits or not".

The increase will start in 2013 when the Universal Credit comes into force.

The government's new welfare payment system will replace a number of existing benefits.

Losing £25 a week in benefits would represent around 37% of the present rate of jobseeker's allowance.

The prime minister, who is in Australia for the Commonwealth Heads of Government Meeting, said: "People need to understand if they commit a crime they will face the consequences.

"The system as it stands at the moment is far too soft and does not always send the right signals.

"If you commit a crime and you are on benefits, you can no longer expect to get away with paying the bare minimum."

Work and Pensions Secretary Iain Duncan Smith said the summer riots showed that many people did not think about the consequences of their behaviour.

Losing a significant amount of their benefits, he believes, will make people who cause trouble feel the full effects of their actions.

"The PM and I were clear that we would look at all parts of the benefit system and ensure that people feel the full effects of their actions," he said.

We should be giving the courts the maximum possible freedom to make sure people pay for their crimes whether they're on benefits or not. Liam Byrne, Labour

Rioters' benefits

"I do not want to be in the business of leaving people without any money to support themselves but, equally, individuals must know that they cannot commit crime that impacts on the livelihoods and the communities of hard-working people without consequences."

Of the 1,350 people who appeared in court for their part in the unrest that hit the streets of England in August, 40% were claiming a state benefit of some kind, according to official figures.

And 35% - 500 - were claiming an out-of-work benefit, compared with 12% of the general working population in England.

In all, 100 people were found to be claiming disability living allowance and 60 had been claiming incapacity benefit. Some may have been claiming both.

Labour said it supported "tough consequences" for criminals.

Shadow Work and Pension Secretary Liam Byrne said: "Labour introduced tough welfare reforms in government, and we've said that the system should encourage responsibility at the top and the bottom.

"It is important that criminals face tough consequences for their crimes. We will look at the detail of this proposal but my view is straightforward.

"We should be giving the courts the maximum possible freedom to make sure people pay for their crimes whether they're on benefits or not."

'Destitute and struggling'

Fellow Labour MP Anne Begg, who chairs the Commons work and pensions committee, said taking too much benefit from individuals who were already poor means they would "resort to crime".

The big deterrent is getting caught, or the fear of getting caught, not what happens afterwards. Frances Crook, Howard League for Penal Reform

"My biggest fear is that it will leave people destitute. Twenty-five pounds is a huge chunk to take. Part of the reason so many people default is that they struggle to pay the fine in the first place."

Stephen Lloyd, the Lib Dem MP for Eastbourne, said it was a "drastic" measure but he supported it as part of a need to break the benefit cycle and force people to "take responsibility" for their actions.

Mr Lloyd, a member of the select committee, described the plan as "very tough, but justified because it is only implemented if people fail to pay fines".

He said he only supported the proposals because "the government is putting so much into the apprentice and work programmes" to help people into work and off benefits.

But Frances Crook, chief executive of the Howard League for Penal Reform, said she was very disappointed at the policy.

"There's no evidence that taking additional money like this after somebody's committed a crime from their benefits would deter someone from going shoplifting, for example.

"The big deterrent is getting caught, or the fear of getting caught, not what happens afterwards. So, this is an announcement that is made up, it's not based on evidence, and it won't have an impact."