Labour will avoid promising to reinstate the 50p top rate of income tax after it is scrapped today.
Ed Miliband will attack the decision to cut tax in 2013 to 45p in the pound for people earning more than £150,000 when he responds to the Budget.
Labour sources said they believed George Osborne was making a "stratospheric mistake" by reducing the headline rate at this time.
However, they confirmed Mr Miliband would steer clear of pledging to reverse the cut, as it was too early to start writing Labour's next election manifesto.
The party leadership is also wary of being painted as a tax-raising party, even when it comes to the highest salaries.