Prime Minister David Cameron has insisted that the Conservative-Liberal Democrat coalition is "as important and necessary" now as it was when the two parties came together in Government two years ago.

In a joint appearance with Deputy Prime Minister Nick Clegg, Mr Cameron insisted the Government could not "let up" on its deficit reduction strategy but said it was "not just about the dry numbers of the economy".

He promised to get behind "families that work hard and do the right thing".

Amid heightened tensions between the Tories and Lib Dems after the two parties' poor showing in last week's local elections, Mr Cameron reaffirmed his commitment to the coalition formed in May 2010.

"I believe the need for that coalition - two parties working together to solve the problems we have in our country - I think is as important and necessary today as it was two years ago," he said.

The Prime Minister said the coalition would keep to its "difficult" spending plans to tackle the country's debts.

"We can't let up on the difficult decisions we've made to cut public spending and to get the deficit and debt under control.

"I know it's hard, I know it's difficult, but when you've got a debt problem the one thing you mustn't do is keep adding endlessly to that debt."

He said the Government needed to keep interest rates low, which would help firms expand and families cope with their mortgages, and "redouble" its efforts to promote economic growth.

The Prime Minister added that he and Mr Clegg were driven by the desire to create something "more worthwhile" than Labour.