Tony Blair has pledged a crackdown on disruptive schoolchildren and their parents.

Speaking in Manchester following a week dominated by headlines on street crime and violent children, the prime minister acknowledged that a breakdown in classroom discipline had spilled over into the nation's streets.

"It is completely unacceptable that young people out of control, excluded from school, are left to roam the streets causing misery and mayhem in local communities," he said.

Soaring statistics for politically sensitive street robberies - "muggings" - are largely accounted for by mobile phone thefts and "playground-style" offences between school-age children and teenagers.

And following Wednesday's Downing Street law and order summit the PM is determined to make schools do their bit in the war on crime.

"Schools need to know that the government is on their side and the community is on their side against unruly children and abusive parents."

"This is not just about education. It is about what kind of country we want to be. We see all around us the consequences if families and communities fail: disaffection, lack of respect, vandalism, drugs, violence," he told an audience at the Abraham Moss school.

Education ministers have agreed to expand truancy sweeps with schools, police and councils combing the streets to identify persistent truants and get them back into the classroom.Blair warned that he expected local authorities to use tough powers to punish parents who turn a blind eye to their children's truancy.

"Local authorities have the powers to prosecute parents and enforce parenting orders against those who, by failing to do anything about their child truanting, are colluding in it. I want to see those powers used properly to help us deal with this problem," he urged.

"It is the job of parents to see that their children are at school - and they are breaking the law and failing in their duty if they don't."

The government will require all local authorities to provide an extended timetable for excluded children from September. Pupil referral units will give permanently excluded children extended compulsory schooling and LEAs are exhorted "to insist on attendance and can prosecute parents whose children fail to attend".

Briefing on the speech earlier, Downing Street said out of control school children are now the government's number one education priority.

People should now expect to hear Estelle Morris talking a lot more about the issue, said the PM's official spokesman, and the education secretary was described as feeling particularly strongly about discipline.

On Blair's call for local authorities to make greater use of parenting orders, Number 10 said the measures included fines of up to £2,500 and prison terms of up to three months.

Although the number of children subject to court orders was now in hundreds but should be higher, said the spokesman.

"Don't under-estimate the power of exultation that the powers are there and should be used," he warned.

But shadow education secretary Damian Green hit back claiming that the speech was an acknowledgement of Labour's failure to tackle truancy.

"Five years on we should be seeing the effects of his action, not just more empty words. Truancy rates are going up, and it is not surprising that all too often this leads to the start of a criminal lifestyle," he said.

"Tony Blair's comments show that the government's claim that it has 'sorted' education is a hollow one."