At last a substantial issue has surfaced in the Labour leadership race. It's the deficit and how quickly Labour should pledge to cut spending to tackle it.

Ed Balls has come out fighting against not just the coalition's policy but the one which his own party fought the last election on. Cutting the deficit in half in four years is too ambitious he says. He urges his party to challenge the consensus and to answer critics who attack "deficit deniers" as "growth deniers".

Alistair Darling's policy is still backed by David Miliband. Brother Ed meantime describes it cryptically as a "starting point"- hinting, although not spelling out, that he would, like the other Ed, re-write it.

Meantime, Tony Blair warns about the dangers of not tackling the deficit in language David Cameron must wish he could match.

Old opposition hands advise that it is never wise to spell out what you'd do in government years before an election. Messrs Balls and Blair have now made it hard to avoid. They have, though, created another problem.

If David Miliband wins the leadership contest it would be nigh on impossible to make Ed Balls shadow chancellor since they have publicly disagreed on the most important aspect of economic policy.

PS. After my apology earlier in the week I have a confession. I am involved in what some see as a BBC conspiracy to examine the most important issue of the day. I am travelling down the A1 making a series of films on public attitudes to spending cuts and how to deal with the deficit. They'll be broadcast next week.

This, says William Hague, is "the straightforward truth", in one of the most extraordinary statements I have ever read from a senior politician.

The foreign secretary admits sharing twin hotel rooms with the man he later appointed - at taxpayers' expense - as his special adviser.

Today Christopher Myers resigned his position.

Hague insists that "Any suggestion that his appointment was due to an improper relationship between us is utterly false" before going much further denying that "I have ever been involved in a relationship with any man".

William Hague addresses delegates at the Conservative Party conference in Manchester, 2009

It goes on to reveal a sad, and up till now private, story about his marriage.

Ffion, it says, has "suffered multiple miscarriages" and the couple "are still grieving for the loss of a pregnancy this summer".

Hague knows that this is an open invitation to prurient media organisations to challenge the truth of his statement.

It is also an invitation for public sympathy. It is a story that, in tomorrow morning's papers, will rival the tales told by Tony Blair.

There's an old saying: don't look in the crystal ball, read the book.

The re-opening of old political wounds will be enough to make some refuse to listen to what their former leader says.

Many may bridle at his refusal to apologise for Iraq, to condemn David Cameron's planned cuts or to accept that the banking crisis has made the case for more government and more regulated markets.

There will, though, be some who do listen to the Labour Party's greatest communicator and unrivalled election winner.

His message to them was clear. Don't do what our party has always done and allow one election defeat to be followed by others. Abandon the New Labour path at your peril. In other words - though he never says so explicitly in his book or his interviews - vote for David Miliband to be our next leader.

PS. I will turn my attention to William Hague's extraordinary statement a little later.

I would like to apologise for my reporting of the relationship between Tony Blair and Gordon Brown in the years they were together in government. Some said it was tittle tattle, others that it was speculation, a few dared to suggest that it was fabrication.

I now accept that I made mistakes. Things were worse - much worse - than I reflected at the time.

I did not report then but now can that:

• Tony Blair blamed Gordon Brown for starting the cash for honours row which led to the first ever police investigation into a serving prime minister

• Gordon Brown threatened to trigger that row if he didn't get his way on a policy which affects the pensions of millions of voters

• Mr Blair did renege on a deal to stand down before the 2005 election

• He did not sack Gordon Brown because he believed that "let loose" he might lead a left wing rebellion

• The PM turned to drink to deal with the stress of dealing with someone he regarded as "very very difficult" and "maddening"

• Tony Blair knew that Gordon Brown would be a hopeless prime minister

Tony Blair's memoirs remind me of Princess Diana's extraordinary Panorama interview. They confirm that what was reported about what happened behind the scenes was just the half of it.

Over breakfast tomorrow morning a few people will open envelopes containing a ballot paper allowing them a say in who becomes Labour's next leader and potentially our next prime minister.

Many will, instead, open their newspaper and listen to the radio to learn the views of the last person to win an election for the party.

All the candidates insist that they want to move on from the past but the publication of Tony Blair's memoirs and his verdict on Labour's 13 years in power and the election his successor lost will make that impossible.

Besides, it is now many weeks since this contest began and it has been dominated not by a policy debate but by a mixture of personality and subtle positioning in relationship to the past.

There is one issue - a crucial one - which does divide the candidates - it is how fast to curb public spending in order to bring down the deficit.

All agree the coalition is moving too far too fast but Ed Balls says that even the last government's plans were too drastic.

With this contest reaching the point of decision and with the past being re-lived there will, of course, be more tension ahead.

However, students of history will note that this is a long, long way away from the bitter and divisive contest which elected Michael Foot and split Labour 30 years ago.

Whoever wins wants to have a chance to write their own prime ministerial memoirs.