George Osborne is looking at scrapping the 50p top rate of tax in his 2013 Budget, as evidence mounts that individuals are going to great lengths to avoid the levy. 

The Office for Budget Responsibility said it had assumed £2bn of tax revenues for the 2009-10 tax year would not be collected in 2010-11.

It believes companies had paid bonuses just before the 50p rate was introduced and business owners paid themselves large dividends to avoid the tax, the Financial Times reported.

Osborne’s team insist there is no timetable for scrapping the 50p rate but all the political signals from the Treasury and senior coalition figures suggest that top earners have just two more years to endure the “temporary” levy.

The chancellor said in his Budget that it would be wrong to cut taxes on people earning more than £150,000 while others on much lower incomes were making “sacrifices” but gave a strong signal that reform was on the way.

“I am clear that the 50p tax rate would do lasting damage to our economy if it were to become permanent,” he said. “That is why I regard it as a temporary measure.”

The chancellor has said it would be inconceivable to scrap the 50p rate before 2013, the time his fourth Budget is due, when the public sector pay freeze comes to an end.