Chancellor George Osborne has said the Conservatives will not raise income tax or national insurance if they are returned to power in the General Election on May 7.

David Cameron wrong-footed Ed Miliband in the final Prime Minister's questions before parliament was dissolved when he gave a firm commitment not to raise VAT.

In a joint interview by Mr Osborne and Mr Cameron with The Sun, the Chancellor confirmed that that assurance also extended to income tax and national insurance, matching similar assurances from Labour.

"You have a very clear commitment from us that we are not going to increase VAT, national insurance or income tax. That is our commitment to working people, that we are there to help them," he said.

Mr Cameron confirmed that he intended to keep Mr Osborne as Chancellor if the Conservatives are back in power.

"The team is the team. You don't want to change the person who has driven our economic performance, and has been at the helm of it," he said.

Liberal Democrat Chief Secretary to the Treasury Danny Alexander said: "The Lib Dems committed weeks ago to not increasing the headline taxes that most people pay - VAT, national insurance and income tax. Now the Tories are playing catch-up.

"But there's one big difference. To meet this commitment and finish the job of balancing the nation's books, we will raise taxes a little on the best-off in society and from the banks. That's the fair way.

"On the other hand, the Tories have ruled out any tax rises and are offering a rash of unfunded tax cuts. Their plan to balance the books is all on the backs of the working-age poor.

"Their new commitment on headline taxes means they will need to take the axe to our vital public services and inflict truly damaging cuts. With the Tories it's a case of giving a little with one hand, but swinging the axe with the other."