The Government's strategy for tackling poverty will be heavily criticised in two separate reports published today.

The New Policy Institute, an independent think tank, said moves to tackle poverty and social exclusion which have been pursued since the late 1990s had lost momentum and that a new approach was needed.

The most serious setback in the anti-poverty campaign had been an increase of 200,000 children living in poverty during 2005/2006, its report claimed. It added that this brought the total number of children living in poverty to 3.8 million for that year, and meant there had been no sustained progress on the issue in three years.

Meanwhile, in a separate Treasury select committee report, MPs said that the Government's commitment to halving child poverty by 2010 could be in doubt because it has not explained how the target will be met. The report expressed concern "that the Government may have drawn back from a whole-hearted commitment" to meeting its target.

It warned that any backtracking would represent a "conscious decision to leave hundreds of thousands of children in poverty for longer than is necessary".

According to The New Policy Institute, although the overall number of children living in poverty had fallen by 600,000 since the Government first made its pledge to end child poverty in 1999, it was still 500,000 short of the target it should have reached in 2004/2005.

The group said tax credits now took around one million children a year out of poverty, but the number of children living in working families who needed tax credits to escape poverty was rising.

At the same time, it said half of all children living in poverty were part of a working family, a similar level to a decade ago, suggesting low wages continued to be an issue.

The report, published by the Joseph Rowntree Foundation, found that out of 50 indicators of poverty and social exclusion, nine had worsened in the past year, mainly in key areas of income and work.

But it added that there had been improvements in seven indicators, particularly primary education, premature death and homelessness. Peter Kenway, who co-authored the report, said: "Progress on child poverty has stalled at a level that is only halfway to the target set for two years ago.

"Tax credits may be working, but they are not enough on their own. Yet the Government's budgetary and legislative programme set out this autumn contains no substantial new ideas about what should be done."

The report added that there were also rising unemployment levels among people aged under 25 while the value of social security benefits for working age adults was falling in relation to earnings.

More women than men still belonged to households in poverty, but the gap had closed since the mid-1990s.

A Treasury spokesman said: "The Government is working towards the 2010 target by getting more people into work and making work pay, including through the national minimum wage and tax credits."