Speaking this morning in Milton Keynes, Cameron said spending cuts to be announced in the emergency budget later this month will be “unavoidably tough”.
He said: “What I can tell you today and what we did not know for sure before, in fact what we could not know, because the previous Chancellor of the Exchequer did not make the figures available, is how much the interest on our debt is likely to increase in the years to come.
“Now we have looked at the figures. Based on the calculations of the last government, in five years’ time the interest we are paying on our debt is predicted to be around £70bn. That is a simply staggering amount.”
Cameron said the UK’s national debt stands at £770bn and is set to double within five years to £1.4tn.
He said: “Because the legacy we have been left is so bad, the measures to deal with it will be unavoidably tough.
“We are doing this because we have to, driven by the urgent truth that unless we do, people will suffer and our national interest will suffer. But this government will not cut this deficit in a way that hurts those we most need to help that divides the country or that undermines the spirit and ethos of our public services.”
Cameron said Chancellor George Osborne and Chief Secretary to the Treasury Danny Alexander will tomorrow publish the framework for this year’s spending review.
The PM said they will explain the principles that will underpin the Government’s approach and the process it intends to follow, including a process to “engage and involve the whole country in the difficult decisions” that will have to be taken.