Q&A: Return of the 50p top rate of income tax?

Shadow chancellor Ed Balls has promised to reintroduce the 50p top rate of income tax for people earning more than £150,000 if Labour wins the next election.

The previous Labour government increased the top rate from 40p to 50p in 2010, but the current government cut that to 45p with effect from April last year.

So what is the 50p tax rate, and why is it such a central issue for politicians in the run-up to the next election?

What is the 50p tax rate?

Why does Ed Balls want to bring it back?

How much would it raise?

What do the coalition parties say?

What do supporters of the 50p top tax rate say?

What do critics say?

How has the top rate of tax changed over the years?