TWO aircraft carriers being built on the Clyde will cost billions more than planned, take longer to complete and not carry aircraft for a decade, a scathing report by MPs today warns.

The Commons Public Accounts Committee (PAC) warned the costs to the taxpayer could be even greater than the currently predicted £6 billion.

The full costs will not be known for at least another year.

The UK Government said last year it would continue the carriers project. But Coalition ministers attacked the last Labour government, saying the contract made it more expensive to scrap than to build the carriers.

However, the UK Government announced changes to one of the ships and that neither would carry aircraft until 2020.

The report said there is still “considerable uncertainty” about the cost of modifying one of the carriers to accommodate a different kind of fighter jet.

Margaret Hodge, the chairwoman of the PAC, said these and other changes in the Coalition’s Strategic Defence and Security Review last year “have changed the risks and costs involved in ways that are not fully understood”.

“Rather than two carriers, available from 2016 and 2018, at a cost of £3.65bn, we will now spend more than £6bn, get one operational carrier and have no aircraft carrier capability until 2020 – almost a decade,” she added.

MPs also accused the Ministry of Defence of focusing on “short-term” savings as it grappled with a £38bn budget black hole.

Labour said there was a “gaping hole” in the Government’s credibility on defence.

Jim Murphy, the Shadow Defence Secretary, said: “Yet again we have a respected body giving a damning assessment of the defence review.”

Philip Hammond, the Defence Secretary, said: “When this Government came into power, the Queen Elizabeth class carriers were already £1.6bn over budget. As part of an overall package of measures taken in the Strategic Defence and Security Review we have reduced overall spending on the Carrier Strike Programme by £4.4bn over the next 10 years.”