Alastair Darling’s first Budget on Wednesday could dent the pockets of high earners through increased National Insurance contributions (NICs) and bigger stamp duty bills on high-value homes.

In spite of fears of recession, worsening government finances offer little scope for giveaways – and may force tax rises. Accountants Grant Thornton suggest that the 1 per cent NI contribution payable on earnings over about £40,000 might be doubled to 2 per cent. This would mean an effective top rate of tax of 42 per cent, said Mike Warburton, senior tax partner.