FAMILY security will be the priority for next week's Budget, David Cameron has insisted, as the Liberal Democrat leadership warned him against any major pre-election tax giveaway.

With just a week to go before his last economic statement before polling day, George Osborne is said to be considering a number of eye-catching populist tax breaks, including: raising the tax-free personal allowance by another £200 to £11,000, benefiting 27m people.

With many believing the May 7 General Election will be won and lost in Scotland, the Chancellor has already signalled a tax cut for the embattled North Sea oil industry, possibly going as far as reversing most if not all of the 2011 12 per cent tax hike on the sector, and there are suggestions he might also cut duty on scotch whisky.

With the so-called quad of Mr Cameron, Mr Osborne, Deputy Prime Minister Nick Clegg and Chief Secretary to the Treasury Danny Alexander meeting last night to thrash out the Budget details, the PM earlier made clear the Budget would be "designed around and centred on Britain's families".

He said: "For the mum who's up and out the door before six o'clock, the dad who gets home from work when everyone else has gone to sleep, the children who are hoping for a holiday at the end of the year, we want families like this to feel secure."

Declaring that his motto in life was "family first," the Tory leader said: "Financial security for families is one of Government's foremost duties. It's what I'm in politics to deliver; a better life for you and your children."

But Vince Cable, the Lib Dem Business Secretary, insisted that there could be no giveaway Budget next Wednesday.

"Nobody would believe it was credible," he declared. "We know that there are continuing budget problems and that therefore we have to be restrained in what we do."

The London MP added: "Certainly, my side of the Coalition will be arguing for a modest Budget. It may well have some pleasant surprises in it but it would be completely wrong under current circumstances to have big tax cuts or big spending commitments."

Meantime, the Institute for Fiscal Studies pointed out that raising the personal allowance would mainly help middle-income households and that help for low earners would be more effectively delivered by raising the threshold for National Insurance contributions.

Reports have already suggested this is another option Mr Osborne has been considering.