Mandelson to back Brown's budget deficit plans
For the business secretary to declare that he backs government policy would not normally be a news story.
However, for weeks Lord Mandelson has remained uncharacteristically silent in public whilst privately expressing deep frustration at Gordon Brown's approach to tackling Britain's budget deficit.
He's been concerned that the prime minister's failure to spell out the need to make public spending cuts has reduced the government's credibility.
Today though Lord Mandelson insists that the government's plans are "far more credible than they are given credit for" and stresses that spending reductions, tax increases and economic growth are all vital to reducing the deficit.
All this is designed to reassure nervy markets who can see for themselves the gulf between the words of the business secretary and the chancellor on the one hand and the prime minister on the other.
Last night the shadow chancellor George Osborne seized on the warning by the world's biggest bond investor, Pimco, that Britain faced seeing its credit rating downgraded and that it would be selling off UK government bonds this year (see more on this on my colleague Robert Peston's blog).
The head of Pimco's European investment team is the brother of the cabinet minister who is said to have Gordon Brown's ear now - his former economic adviser Ed Balls - allowing Osborne to claim that even the Balls family don't trust the government's deficit reduction plans.
Mandelson's also had concerns that Labour risked looking like it was turning its back on the New Labour coalition and relying on a core vote strategy.
Thus, he stresses that the government will "always be vigilant" that the tax burden on businesses and highest earners "does not become so great that it damages our long-term competitiveness".
He goes on to tell his party to focus on "the politics of production" - wealth creation - not "the politics of distribution".
UPDATE, 11:55: I have now had the chance to read the full text - as against a few extracts - of Peter Mandelson's speech.
At its heart is an important argument - clearly laid out - but there is also an intriguing political admission and an important omission.
Peter Mandelson's argument is that economic growth stimulated by government activism is the best cure for the deficit. He warns that cutting spending faster - as the Tories advocate - risks "kicking the prop" from the British economy.
Even if quicker deficit reduction produced lower interest rates, he argues that might not be enough to get the economy growing again as the Japanese discovered.
Now for that political admission. Reviewing the growth policies of recent decades the business secretary describes the privatizations of the 1980's made by the Margaret Thatcher government as "timely".
What's more he concedes that industrial relations underwent a valuable sea change.
Perhaps most importantly though, Mandelson does not use the word "cuts" which he dearly would like the prime minister to use. Instead in his speech he talks about "real reductions" and impacts on other services which "cannot be painless".
And that omission is most striking when it comes to what's going on in his own department. Whilst hailing universities as a possible source of future growth he doesn't point out that their budget is taking what he would call "real reductions" and they call painful cuts.