A project pioneered in Bristol to tackle problem families will be rolled out across the country, Gordon Brown is to reveal today.

The Prime Minister will outline his plans to replicate the "tough-love" Family Intervention Project that forces troubled mums and dads to take expert help to curb anti-social behaviour.

That includes parenting classes for up to 80 families within two years at The Park in Knowle West, the Greenway Centre in Southmead and a range of other measures such signing behaviour contracts.

In his speech to Labour's annual conference in Brighton Mr Brown is due to say: "Most mums and dads do a great job, but there are those who let their kids run riot and I'm not prepared to accept it as simply part of life.

"Family Intervention Projects are a tough-love, no-nonsense approach with help for those who want to change and proper penalties for those who don't.

"Family intervention partnerships could save Britain up to three billion pounds in the long run. But more than the money we could save, I'm excited by the lives we could change.

"So I can announce today that the parents of any child guilty of anti-social behaviour will now be automatically subject to a parenting contract. These are binding contracts which require people to take one-to-one support or lose their benefits.

"And I can announce today that we will double the number of these family intervention projects so that for the 50,000 most chaotic families and their 100,000 children there will be clear rules, and clear punishments if they don't comply."

Bristol was one of first cities to trial the scheme but the government will pledge to extend the measures to every problem family by 2015.