ECONOMIC credibility.

It is the key to winning the next General Election.

At present, the polls suggest that, despite the horrendous hole Britain's economy is in, the Tories remain ahead of Labour on who is best to manage the nation's money.

Part of the art of Opposition is timing; when to hold back and when to put flesh on the bones of policy.

This week, responding to criticism that Labour had been looking particularly skeletal, the party leadership decided to begin the fleshing-out process,

But it did not go well.

On Monday, Ed Balls, the Shadow Chancellor, revealed Labour would scrap the winter fuel allowance for better-off pensioners – a Liberal Democrat suggestion. But this raised concerns about the party's commitment to universal benefits.

Also, the Shadow Chancellor raised the prospect of regional benefits, that is, paying different rates in different parts of the UK. He pointed to the higher housing costs in London.

Yet this might be the road to political perdition. The Coalition toyed with the idea of regional pay and quickly realised the electoral price of proposing paying public sector workers at different levels in different parts of the country. One Nation it ain't. Not stopping at winter fuel allowance, we now learn Labour would not reverse the Coalition withdrawal of child benefit for better-off families; a policy it once denigrated.

Today, Mr Miliband will talk tough and insist Labour would reform social security "with the right values". This will mean a cap on welfare spending; Labour voted against the Coalition's £26,000 benefit ceiling last year.

While it supported the idea of a cap in principle, it felt the form taken was unfair. Mr Balls spoke of "iron discipline".

Mr Miliband today will promise a "laser focus" on spending money wisely.

He will also talk of building more homes to reduce housing benefit costs, tackling low pay, and will float the idea of paying different rates of Jobseeker's Allowance depending on how long a person has paid into the system. This again might prove rather divisive.

The ill-timed leaking of the policy U-turn on child benefit provided David Cameron with a large stick with which to beat Mr Miliband at PMQs.

Nick Clegg denounced the Labour "flip-flop", the SNP accused it of being "joined at the hip" with the Tories on welfare, while union chief Mark Serwotka accused Mr Miliband of parroting the Conservatives and offering "austerity-lite".