Will Mandelson swap politics for business?

Instead of seeking "dignity in retirement" as Ed Miliband advised, the irrepressible Peter Mandelson is setting up in business as head of an international consultancy.

But the man famous for being the most experienced spin doctor in British politics did not quite manage to keep control over the publicity around his new venture. The announcement was planned for next week, but the news seeped out early after a journalist at Sky News spotted documents deposited at Companies House.

They showed that a new firm called Global Counsel LLP was incorporated on Wednesday of last week. Its financial year starts from today. The only director named is Lord Mandelson's former special adviser, Benjamin Wegg-Prosser, but there will also be a corporate director nominated by WPP, the world's largest media group, which is backing the venture.

The address given for Global Counsel is that of WPP's head office in the City of London. WPP also owns the City firm, Finsbury, run by Roland Rudd, a former Financial Times journalist who is close to Lord Mandelson.

David Muir, Gordon Brown's former director of political strategy, is also expected to play a role in the new company. Before taking up his post in Downing Street in March 2008, he was a right-hand man of WPP's chief executive Martin Sorrell.

The company will be able to offer expertise based on Lord Mandelson's years as a Cabinet minister and EU Commissioner and on his associates' understanding of the inner workings of Downing Street.

Mr Wegg Prosser, 36, went to work for Mr Mandelson in 1996, directly from university. He later worked in the media, but remained close to his former employer. In 2005, he went back into politics to head up Downing Street's communications unit.

Although Lord Mandelson left office in May, after his efforts to form a Coalition Government with the Liberal Democrats fell through, he has resolutely refused to fade away.

Within weeks of leaving office, he published his revelatory memoirs, entitled The Third Man, which was ranked 417th in the Amazon bestseller list yesterday. Last week he was the subject of a fly-on-the-wall documentary by Hannah Rothschild, who spent eight months trailing the then Business secretary.

But it was made clear to him that there would be no place on Ed Miliband's shadow cabinet, even if he had wanted one, after more than 24 years as a major player in Labour Party politics. During the leadership election campaign, Ed Miliband was asked about the old spin doctor's political future and replied: "I think all of us believe in dignity in retirement."

Lord Mandelson took offence at this remark and apparently does not accept that his days as a political mover and shaker might be over.

Interviewed this month by Total Politics magazine, he said: "I want to continue as a trusted and respected grandee or great uncle...I felt hurt, I felt denigrated by some of Ed Miliband's remarks. Talking about me in terms of 'dignity in retirement', I felt as if I was being unfairly treated and packed off rather prematurely to an old-folks' home."