The cash-stricken Ministry of Defence has finally succeeded in balancing the books, Defence Secretary Philip Hammond will announce on Monday.
Hammond is expected to tell the Commons that he has plugged the £38bn "black hole" in the defence budget which ministers said they inherited from the last Labour government.
"In terms of reducing the size of the Civil Service, the Army and the Air Force, we shouldn't have to do any more over and above what we've already announced," he said in an interview with The Sunday Times.
In a major U-turn last week, Hammond announced he was scrapping plans to acquire a more capable version of the US-built Joint Strike Fighter for the Royal Navy's new aircraft carriers.
He said the decision - in the face of soaring costs - to revert to the jump jet variant ordered by Labour was the "last big piece in the jigsaw".