LONDON, July 24 (Reuters) - Growing anti-social behaviour has turned Britain's cities and towns into "no-go areas" after dark, the chairman of an influential parliamentary committee said on Tuesday.

Dealing with louts and tearways costs 3.4 billion pounds a year, but the Home Office has still not discovered the most effective way to tackle the problem, the Public Accounts Committee (PAC) said.

"No civilised country should have to put up with what can seem like an occupying army loose in the streets," said Edward Leigh, the PAC's chairman.

"After dark, our cities and towns are fast becoming no-go areas, with behaviour there ranging from drunken skylarking and intimidation, to out and out criminal activity."

Dealing with anti-social behaviour is a priority issue for the Labour government. Leigh said it had introduced "a barrage" of new powers for the police and local authorities.

But the PAC said the Home Office had no idea which of these measures were the most effective.

National Audit Office research last December examined 893 cases involving three powers -- ASBOs (anti-social behaviour orders), acceptable behaviour contracts and warning letters.

The study found that in 65 percent of cases individuals desisted from nuisance behaviour after one intervention.

However, a hard core repeatedly cause problems. More than half of those given ASBOs broke the terms of their orders while one individual, with 271 criminal convictions, contravened his ASBO on 25 occasions.

The PAC said enforcement against those who breached their orders should be "absolutely rigorous", warranting prison terms in some cases.

"They (the government) go on about the record number of ASBOs given out whilst repeatedly ignoring the fact that nearly two-thirds are breached," said David Davis, the Conservatives' home affairs spokesman.

"This failure comes about because Labour's approach has been to get the headline and ignore the problem."

The Home Office said that in 94 percent of local authority areas, the public perceived there had been a fall in yobbish behaviour from 2003/4 to 2005/6. It promised to study the report carefully.

"We recognise that there are a small minority of offenders committing the vast majority of anti-social behaviour and expect enforcement action to be rigorous," said Home Office minister Tony McNulty.

"Breach of an ASBO is a criminal offence and criminal penalties apply."