Use of the silver Rover is a present to the Labour Party from the Ministry of Sound, the nightclub owned by James Palumbo, estranged son of the Tory peer Lord Palumbo, but Mr Mandelson has apparently enjoyed much of the benefit.
The news that Labour's head of election planning has achieved chauffeur- driven status is bound to cause resentment among his colleagues. Mr Mandelson is seen as being at the heart of New Labour and is deeply disliked by those on the left. Many people in the party see him as a dark force behind Tony Blair's throne.
Tensions between him and John Prescott, the deputy leader, are reported to have escalated recently, with both men vying to be chosen for the post of Deputy Prime Minister in the event of a Labour victory.
Mr Blair is the only other Labour figure to enjoy the luxury of a chauffeured car, through access to an official government car. Mr Prescott has a Rover lent by the manufacturers.
Until recently, Mr Mandelson could be seen driving his own green Rover. Since the beginning of December, however, he has been able to travel in more style.
He is known to be friendly with Mr Palumbo, whose club uses the same advertising agency as Labour and who has run left-leaning campaigns to persuade young people to vote.
Ministry of Sound staff say Mr Mandelson is a visitor. He was seen dancing in his tuxedo at the Ministry of Sound's fifth anniversary party in September and chatting to Mr Palumbo. The club is a stone's throw from Labour's headquarters in south London.
Mr Mandelson, the MP for Hartlepool, is abroad with friends and the car was said last night to be in the care of its chauffeur. However, he phoned his staff to ensure that his views on the matter were recorded.
"This is a welcome contribution to Labour's campaign effort," Mr Mandelson said in a statement. "We are a professional mobile team at Millbank and the days of relying on a penny-farthing machine are over."
His aide, Benjamin Wegg-Prosser, said other staff at Labour's Millbank media centre had been able to use the car. Mr Mandelson had consulted the Parliamentary Commissioner for Standards, Gordon Downey, about it and had agreed as a result to declare it in the register of members' interests, he said. If the cost of the car ran to more than pounds 5,000 it would appear in the party's accounts, he said.
"We welcome all the help and assistance which people can give to our campaign," Mr Wegg-Prosser said. "The car has been given to the Labour Party by the Ministry of Sound for the use of Mr Mandelson and staff at the party's media centre."
Mr Wegg-Prosser could not say who else had used the car or how often, or what kind of Rover it was. Tony Blair's press officer, Alastair Campbell, said he had travelled in it himself and it was used for courier work.
A Conservative Party spokesman said the gift was rather appropriate. "It is ironic that the Ministry of Sound are lending a car to the Minister for Soundbites," he said.
Mr Palumbo, 34, founder of the Ministry of Sound, is probably best known for his long-standing feud with his father, against whom he took legal action over the multi-million-pound family trust.
He was also the creator and backer of the creator of "Rock The Vote", the music industry's attempt to get young people to the polls, which began in a blaze of publicity last February.
Although the campaign's organisers were keen to stress its neutrality, Tory supporters of Rock The Vote apparently felt that Labour had hijacked it.
Rock the Vote was superseded in October by a pounds 250,000 "Use Your Vote" advertising campaign run by the Ministry of Sound record label.
A source at the Ministry of Sound denied yesterday that the car was evidence of the club backing Labour.
"We have helped in many different sorts of ways people from all political parties," he said. He refused to say which other parties had been helped and in what ways.Reuse content