Every household pays £900 a year to cover bungled Government projects

Labour has squandered a staggering £23billion of taxpayers' money by failing to control the spiralling costs of hundreds of flagship schemes, figures reveal.

The 2012 Olympic Games in London, the Channel Tunnel Rail Link, a super-computer for the NHS and the Eurofighter military aircraft are among the projects that have soared over budget. The wasted money would have been enough to build nearly 100 new hospitals.

MPs and low-tax campaigners said the sum squandered was "criminal".

Philip Hammond, Tory Treasury spokesman, said: "It is outrageous that hard-working British families have been hit to the tune of £900 each to pay for Labour's project cost overruns.

"During his ten years as Chancellor, Gordon Brown has overseen the wasting of taxpayers' money on an industrial scale. Labour's inability to manage projects effectively partly explains why he has spent so much and achieved so little."

The TaxPayers' Alliance campaign group uncovered the amount wasted by investigating the official budgets of 305 Government schemes.

These included new roads, hospitals, science facilities, computer systems, art galleries and defence systems. All the schemes have been completed in the past two years or are ongoing.

Researchers compared the initial estimated budget for the projects with the final cost or latest estimate. They discovered that the average overrun for a project was 34 per cent.

The budgets of 14 projects overran by more than the Millennium Dome, which cost £204million more than planned.

The biggest drain on the public purse was the installation of the Department of Health's crisis-hit national computer system, designed to hold millions of NHS patient records.

The scale and complexity of this project, thought to be the world's largest civilian IT project, means it is already years behind schedule. The original cost was £2.3billion. But the latest estimate is £12.4billion - 439 per cent over budget.

The budget for the 2012 Olympics has spiralled from £2.4billion in 2005 when London won the battle to stage the Games, to £9.35billion now. The bill for the Ministry of Defence's Astute class nuclear submarines, being built by BAe Systems, has soared from £2.5billion to £3.6billion.

And a wave of hospitals built under the controversial private finance initiative scheme have seen costs rocket by millions of pounds.

The worst two departments for overruns were the Department of Health and the Department for Culture, Media and Sport.

Matthew Sinclair, policy analyst at the TaxPayers' Alliance, said: "These figures expose a consistent pattern of poor project management.

"Taxpayers are footing the bill for the failure of politicians and civil servants to manage large projects effectively."

Experts said the problems stemmed from a failure by departments to specify exactly what they wanted, underestimating costs to get a project approved and paying over the odds in an attempt to solve the problem.