A Cabinet minister has given the strongest indication yet that the Government will have to cut spending after the next general election.
Environment Secretary Hilary Benn said that his own department was facing budget reductions, and there would have to be "real choices".
When it was put to him that his comments would be interpreted as an admission that spending would fall in real terms, Mr Benn repeatedly refused to clarify them further.
The intervention came despite Gordon Brown insisting that the next election will be a decision between "Tory cuts" and Labour investment.
David Cameron has accused the Prime Minister of being "caught red-handed" giving misleading figures to the public over the main parties' plans.
Speaking on BBC Radio 4's Any Questions, Mr Benn said: "For me this argument is all about what kind of values do you want to inform the decisions about where we spend money?"
He went on: "Of course given the amount of debt that we have taken on to try and help us through the recession, and we should make no apology about doing that...in the end politics comes back to values that inform the choices that you make."
Mr Benn added: "If I look at my department's budget, it is going to go down a bit and therefore we will have to prioritise."