Nobody has a monopoly on political ideas, insists Darling

Alistair Darling denied stealing Tory policies as he faced Opposition claims that his first tax and spending statement as Chancellor was already unravelling.

Mr Darling sought to shrug off criticism that he had copied Tory plans to cut inheritance tax, hit foreign UK residents who claim non-domicile tax status and bring in a "flight tax" to help combat climate change in his pre-Budget report and government-wide spending review on Tuesday.

In a round of media interviews, he insisted that he began working on the tax changes soon after becoming Chancellor in June. "I don't think anybody has a monopoly on one particular idea or another," he said. "Surely what people are looking for is a long-term vision for the country? I have also put in place a long-term framework for this country, so that we have got stability, we can keep interest rates down, we can keep inflation down – that helps people's living standards."

The Tories seized on an analysis by the Institute for Fiscal Studies which suggest that taxes will rise by £2,600 for the average family over the next five years.

George Osborne, the shadow Chancellor, said: "Gordon Brown's budget is unravelling because people look at the small print. The Chancellor said the budget represented a tax cut. But independent experts now find that there is a £50 a week tax bombshell for families. This shows just how cynical and calculating Gordon Brown's Government has become."

Denying that the Tories would have to go back to square one when they draw up their election manifesto, he said they had "plenty more ideas" such as ensuring value for money from health and education spending and help for business and families.

The Opposition also accused the Government of imposing a £400m a year "stealth tax" on pensioners for five years by bringing forward the start date of a new cap on the state second pension for people not in company or personal pension schemes. The cap will take effect at least three years before the basic state pension rises annually in line with earnings rather than prices.

Vince Cable, the Treasury spokesman for the Liberal Democrats, said Labour had stolen their ideas rather than those of the Tories. He said: "We had set out this policy on changing the basis of aviation tax, the Tories pinched it from us and now the Government have pinched it from them. For the Tories to be bellyaching about it, it's like a gang of thieves complaining about their houses being burgled."

Mr Darling was reminded that he attacked a proposal last year to abolish inheritance tax by the former Labour cabinet minister Stephen Byers. He said: "What was put to me there was, why not abolish inheritance tax completely? I was asked a specific question and I gave a specific answer."