By Martha Kearney
Presenter, BBC Radio 4's World at One
"Making Peter business secretary is like making Alastair Campbell [a reformed drinker] minister for booze"- one of Lord Mandelson's friends remarking on his penchant for rich friends.
Yacht's the story: Mr Deripaska luxury vessel is still making political waves
Others shrug off the Deripaska affair as "typical Peter" - one minister described it as an "every day tale of Mandel-folk (and personally I prefer The Archers)".
He was been cleared of any wrong doing by the most senior EU trade official but questions do remain.
Why was he economical, if not downright parsimonious, with the truth when asked about his connections with the Russian billionaire?
The first version was that he had just had drinks on the yacht, then it turned out the commissioner had stayed there.
At first he had met Deripaska in 2006 and 2007, now it seems they met in 2004, the year that Peter Mandelson became EU commissioner for trade. It was that unwillingness to be totally frank which led to his second resignation in 2001.
The EU Code of Conduct for Commissioners states that "commissioners should behave in a manner that is in keeping with the dignity of their office.
Ruling out all risks of a conflict of interests helps to guarantee their independence."
A point I put to Cathy Ashton who was confirmed as Peter Mandelson's successor in the trade portfolio on Wednesday. She of course defended him.
It is interesting that his return to politics has meant headlines dominated by yachts and billionaires.
Perhaps Gordon Brown will regard it as a price worth paying for restoring party unity.
Previously hostile Blairites have now been rallying round. But if more stories emerge about Lord Mandelson, for example that his links with Oleg Deripaska are deeper than admitted, the prime minister may regret his bold decision.
Yachtgate has of course damaged the Conservatives too and the shadow chancellor in particular.
There are many in his party who believe that he has been the victim of a witch hunt but others including senior Conservatives whom we spoke to off the record this week believe that George Osborne made an error of judgement.
One said "There is no evidence of impropriety at all. The issue now is judgement.
Is Peter Mandelson's return good for Labour Party unity?
"The Mandy conversations should never have been leaked to the press. That's an error.
"Quite clearly nobody asked for donations. But, in retrospect, the conclusion they reached should have taken seconds and not as long as it did.
"In the worst scenario, this was a conversation on the possibility of a donation."
Another said: "If a donation had been given it would have been improper. God knows I'm not a fan of Russian oligarchs - I'd need a long spoon to go anywhere near one.
"In retrospect, perhaps he should have steered clear... Obviously, with the economy as it is, the timing is unfortunate."
At least in the short term it will make it harder for the shadow chancellor to carry out his role.
Friday's output figures showed the economy shrinking, the worst economic news since the government came to power, but the shadow chancellor is unavailable for interviews.
He should be leading the charge but that's difficult with Yachtgate hanging over his head.
He may also face an investigation from the Parliamentary standards commissioner after the Lib Dem MP Norman Baker told our programme he thought George Osborne should have declared his stay in Nat Rothchild's villa in the Register of Members' Interests.
"I think it's very important you establish the rules, not just for Mr Osborne's case, but also Peter Mandelson and any other MPs who may have been involved in accepting hospitality from a third party," said Mr Baker.
Another issue may arise too.
One senior Conservative has suggested to me that there is a systemic problem in George Osborne's dual roles as shadow chancellor and election co-ordinator.
My source said that he is de facto chairman both because of Caroline Spelman's weakened position and because he is one of the few Tory politicians able to raise money for the party as he spends so much time with City figures.
This MP believes that leaves the shadow chancellor open to suggestions of improper influence and so one or other job should be taken away from him.
There may be longer lasting damage for the Conservatives too.
Immense pains have been taken to develop the party's policies on social justice. Pictures of their senior politicians in Bullingdon Club white tie will not help that repositioning.
But it should be remembered that despite the apparent revival of Gordon Brown, the Conservatives still have a healthy lead in the opinion polls.
And the prime minister was caught out this week in trying to score a political point.
At Prime Minister's Questions he told Dennis Skinner that this was a serious matter and the authorities should investigate.
Tony Wright, the Labour chair of the Public Administration Committee, was on WATO immediately afterwards.
He told us: "Gordon obviously thinks it was a serious matter, and I suppose in a sense it is a serious matter.
"But we are not talking about corruption here, there was no corruption. We're not talking about law-breaking, there is no law-breaking. What there is is a massive misjudgement.
"I am not sure which authorities Gordon thought he was talking about. The only one I can think of is the Conservative Party."
It's certainly been a torrid week.
Let me leave you with one wild suggestion about the future.
My scenario goes like this: Dominique Strauss-Kahn is forced to resign as head of the IMF because of those problems over his former mistress and then Gordon Brown takes over as the self-styled saviour of the financial world.
He no longer has to fight an election which looks extremely difficult to win and leaves office with his political reputation at least partially salvaged.
What do you reckon?
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