Those earning over £150,000 will pay 50% tax from April 2010.

High-earning Britons will find themselves paying 50% income tax from April 2010, announced Labour’s Alistair Darling in the 2009 Budget.

Presenting his new budget to Parliament, Darling said the 50p tax rate replaces the planned 45p new top rate announced in November’s pre-budget report and will kick in April 2010, a year earlier than planned.

The new rate will only apply to those earning over £150,000 a year, who will also see tax relief on their pension contributions curbed.

The Chancellor said: “I believe that it is fair that those who have gained the most should contribute more.

“In November, I also announced that I was reducing personal allowances for the very highest earners with incomes over £100,000. These allowances are worth twice as much as those of basic-rate taxpayers. I have now decided to fully withdraw the benefit of that allowance for those with incomes over £100,000 from next April.

“Mr Deputy Speaker, these measures are necessary to build our recovery and secure our country’s economic future.”

According to the HM Treasury website, total public spending is expected to be around £671.4 billion this year, around £10,900 for every man, woman and child in the UK. It is set to rise to £701.7 billion in 2010-11.

The Budget is the UK’s annual financial statement, including a review of taxation levels and announcement of spending plans. It is the responsibility of the Chancellor of the Exchequer who works closely with his team of ministerial colleagues and senior civil servants.

Since May 1997, the Treasury has presented two economic forecasts per year - the Budget in the spring, and Pre-Budget Report (PBR) in the autumn.