MUCH higher public spending in Scotland than in the North-East is a price worth paying to prevent the break-up of the United Kingdom, Tony Blair said yesterday.

Giving evidence to MPs at Westminster, the outgoing Prime Minister gave his most honest account yet of the real reasons for keeping the infamous Barnett Formula, which provides extra funding for Scotland.

In recent years, ministers have struggled to defend much higher public spending north of the border, when people in the North-East are significantly poorer.

Only last week, the Scottish Parliament - thanks to funding from London - was able to scrap fees paid by Scottish university students, when English students must pay up to £3,000-a-year.

Asked about the Barnett Formula when appearing for the last time before Commons committee chairmen, Mr Blair replied: "It's part of the balance that we have in our constitution.

"If we want to keep the UK together, the Barnett Formula is a small price to pay for that, even though I understand why it causes concern in parts of England."

Mr Blair added: "When you look around the world - the amount of secessionist pressures there are and the disputes there are within countries - I think we have found a way through that."

According to the most recent figures, Scotland receives £8,265 per head from the Treasury, while the North-East gets only £7,689.

Yet income-per-head north of the border stood at 96.2 per cent of the national average in 2004 - while the North East figure was only 79.9 per cent.

Even Lord Barnett, a former Labour Treasury minister, has spoken of his deep embarrassment that the formula bearing his name - introduced for one year only in the late Seventies - still exists.

Furthermore, the admission that Scots are, in effect, being bribed to stay within the UK comes as a Scotsman - Chancellor Gordon Brown - prepares to move into No.10.

Mr Blair also made plain his belief that the idea of elected regional assemblies is dead, following the heavy "No" vote in the 2004 North-East referendum.

Instead, he pointed to the slow spread of elected mayors as the better way to devolve power, adding: "I make this prediction, in ten years' time we will have elected mayors in most of our big cities."

On elected assemblies, Mr Blair said: "If it was going to work anywhere, it was going to work in the North-East.

"But we found Teesside did not feel the necessary link with Tyneside, that County Durham did not want to be in the same place in terms of government as Newcastle."

Mr Blair was forced to deny weekend reports that he went to war in Iraq fearing that the US had failed to prepare for the aftermath - leading to the ongoing bloodbath.

A series of former advisors have claimed that the Prime Minister was in despair at the failure of the US to plan adequately for the post-invasion period.

But, Mr Blair said: "I wasn't warning about the lack of preparation. I was saying that it was important that we were prepared."

The Prime Minister also set out his "red lines" ahead of this week's European Union summit, insisting he would not sign anything other than an "amending treaty".

The four areas where he would not compromise were the Charter of Fundamental Rights, foreign policy, control of judicial policy and no majority voting on tax and benefits.