Labour tonight accused the Government of inventing a £38 billion black hole in the defence budget to justify sweeping cuts to the military.

Shadow defence minister Kevan Jones claimed the coalition used the financial ''myth'' as a reason for redundancies across the armed forces.

The Durham North MP said: ''It's gone into folklore but there is no evidence this Government has produced to justify it.''

He believed the claim £38 billion of unfunded defence spending was planned when Labour was in power was a ''completely erroneous myth that has been built up by this Government'', adding it was ''a fictional figure''.

Mr Jones added: ''Ministers will have to offer this House the information it needs to take this claim seriously.''

His comments came during a Labour-led Commons debate on defence reform and as ministers prepare to announce which historic battalions or regiments face the axe in the latest round of defence cuts.

Under the Strategic Defence and Security Review (SDSR) of October 2010, the Royal Navy and the RAF have to cut 5,000 jobs each by 2015, the Army 7,000 and the Ministry of Defence 25,000 civilian staff.

''It's becoming clear to many that the Secretary of State has balanced the budget on the backs of our brave servicemen and women,'' said Mr Jones.

''The SDSR has unravelled quickly, displaying the short-term, ad hoc and rushed decision making which, unfortunately, is becoming characteristic of many areas of policy in this Government.

''The decisions taken have left Britain with serious gaps in defence capability.''

But he attacked the Government's much-repeated allegation that a £38 billion black hole existed in the Ministry of Defence (MoD) budget - a black hole Defence Secretary Philip Hammond recently said he had eliminated.

''Last month the Secretary of State told the House he had brought the MoD budget back into balance. Every announcement or decision made by this Government is based on this claim,'' Mr Jones said.

''However, unless we get hard evidence soon it will remain impossible for us to believe these claims.

''Ministers must be honest with our armed forces' men and women who deserve the full picture of the MoD budget so they can understand why they are having to undertake the pain they are under this coalition Government.''

Tory MPs asked Mr Jones how much he believed the black hole was worth, but he repeatedly refused to answer.