David Cameron has renewed the pressure on Prime Minister Gordon Brown over the 10p tax rate.

The move comes ahead of the crucial Crewe and Nantwich by-election.

Speaking at a press conference before setting off to the north west to campaign, Mr Cameron said: "We've got 15 days to overturn Labour's majority of more than 7,000. Obviously it's going to be a tall order but we are going to give it our best shot."

He added: "Our message will focus in particular on the 10p tax rate and how Gordon Brown is hurting the people of Crewe with tax increases just at the moment their cost of living is going up.

"People in Crewe know that the more of them that vote Conservative on May 22, the clearer the message will be to Gordon Brown to do more to help those who have suffered from the tax con Budget."

But, despite being repeatedly pressed on the issue, he failed to give any detail of how how his party would compensate the millions of less-well-off electors who lost out through the abolition of the lower rate.

Mr Cameron continued: "The people of Crewe should ask themselves: if Labour win, won't Gordon Brown breathe a sigh of relief, think 'I've got away with it' and tell Frank Field and everyone else to get lost.

"There is a real impetus there to make sure that the message is loud and clear and people that suffered from the tax con budget are properly compensated."

Chancellor Alistair Darling averted a major backbench rebellion by promising to come up with a package based around tax credits, the minimum wage and additional winter fuel allowance payments.

However, the rebels are now demanding clearer detail of the specific measures.

The Crewe and Nantwich by-election has been forced by the death last month of Labour MP Gwyneth Dunwoody - whose daughter Tamsin is defending the seat for Labour.

Mr Cameron hailed his "very strong local candidate" Edward Timpson.

Meanwhile, Mr Brown has chaired his first Cabinet meeting since Labour's disastrous local election defeats.

The Prime Minister is expected to ditch unpopular policies, such as the 2p rise in fuel duty and pay-as-you-throw litter charges.

But some dissident backbench Labour MPs say the changes won't be enough to avoid losing Mr Brown the general election.

But senior ministers have rallied around their premier in the wake of last Thursday's Labour bloodbath at the polls.

Foreign Secretary David Miliband branded talk of a leadership challenge "utter rubbish", while Justice Secretary Jack Straw and International Development Secretary Douglas Alexander also insisted Mr Brown's position was secure.

Tony Lloyd, chairman of the Parliamentary Labour Party, claimed only "malicious" MPs and those with "personality defects" wanted to depose the PM.

© Independent Television News Limited 2008. All rights reserved.