Today's Daily Telegraph includes a story suggesting that if the Conservatives win power they won't abolish the 50p tax rate until the end of their first time. But the paper rather too readily makes the assumption that the tax won't be introduced before the next election.

The new top rate of income tax is currently due to take effect from April but given the febrile state of UK politics there's no reason to assume that an election won't have been held by then. Gordon Brown may well wish to avoid going to the polls in May, the last possible date for a general election, as John Major did in 1997. An earlier election would also allow Labour to neatly avoid breaking their 2005 pledge not to raise income tax.

In any case, the Conservatives should be asked whether they would be prepared not merely to live with the 50p rate but to actually introduce it. A failure to do so would leave the party vulnerable to the charge that they are prepared to let the less well-off bear the brunt of tax rises.

The story also quotes a Conservative source who bizarrely claims that the 50p rate will "remind people of the worst of Labour". In fact, a YouGov/Telegraph poll carried out shortly after the budget found that 68 per cent of the public support the measure. The finding is tucked away at the bottom of this story.

Labour should exploit the difficulties the tax rate causes the Tories far more than it has done. The 50p rate can be added to the divisions between Boris Johnson and David Cameron explored by my colleague James Macintyre earlier this week. Johnson has called for the Conservatives to unequivocally reject the new rate, accusing Labour of waging a new "class war".

And if Cameron fails to deliver for the right in power, expect the party's unreconstructed Thatcherites to raise this issue again.