Image copyright Getty Images Image caption The Troubled Families Programme was launched in 2012

The government's claim that a project had "turned around" the lives of 99% of England's most troubled families was misleading, MPs have said.

Ministers had not taken into account costs when saying the Troubled Families programme had saved taxpayers £1.2bn, the Public Accounts Committee added.

It also criticised the payment-by-results system for councils.

The government said the scheme had in fact made "significant improvements", but it was willing to learn "lessons".

Former Prime Minister David Cameron launched the £448m scheme in 2012, following the 2011 riots, saying he wanted to improve the lives of 120,000 families in England by 2015.

As part of the scheme, local authorities claimed reward payments for 116,654 families, out of the maximum 117,910 for which they could have claimed, during this period.

The Department for Communities and Local Government said last year that the programme had "turned around the lives" of those assisted.

'Some success'

But the committee's report said: "The implication of 'turned around' was misleading, as the term was only indicative of achieving short-term outcomes under the programme rather than representing long-term, sustainable change in families' lives.

"While there was some success, by claiming that an outcome achieved meant that a family had been 'turned around', the department's use of the term overstated the impact of the Troubled Families programme."

The programme, which was extended for five years in 2015 with an extra £900m aimed at helping another 400,000 families, works on a payment-by-results system.

Under this, councils receive up to £4,000 for each family they help by sending in a dedicated worker, the results being measured against criteria such as improved school attendance, lower crime rates and higher employment levels.

But the committee said this approach had encouraged "perverse" behaviour by local authorities.

This included pushing some families too quickly through the scheme to drawdown payments and "claiming results for families at the margins of the programme in order to meet targets".

The committee's chairwoman, Labour MP Meg Hillier, said the report was "far more serious" than "a slap on the wrist" for ministers.

A government-commissioned report from the National Institute of Economic and Social Research, published in October, also cast doubt on the progress achieved by 2015.

A Department for Communities and Local Government (DCLG) spokesman said: "As the PAC report recognises, the Troubled Families programme enabled local authorities to expand and transform the way local services work with families.

"But of course, there will always be lessons to learn and we have already made significant improvements to the second stage of the programme.

"We will look carefully at the evidence to find out how we can improve the programme further to help some of the most vulnerable people in our society."