The leaders of Britain's three biggest parties at Westminster have gone head-to-head over their plans for tax during the final prime-ministerial debate.

Gordon Brown branded Conservative plans to axe child tax credits for better off families "unfair and immoral".

Tory leader David Cameron said Mr Brown had got his facts wrong and "should be ashamed of what he is doing".

Nick Clegg said the way the tax credit system worked was "unfair" and said his party would fix it.