The police officer who ran the cash-for-honours inquiry is to oversee a new investigation into the Labour Party, The Times has learnt.

Assistant Commissioner John Yates will advise detectives who are to investigate the party’s “proxy donors”.

The move comes after the Electoral Commission’s decision last night to refer the row over Labour’s disguised donations to the Metropolitan Police.

Mr Yates’s appointment will infuriate Labour MPs, who claimed that he was overly aggressive during the 18-month inquiry into allegations that honours were sold in return for loans.

It also raises the prospect that Gordon Brown could become the second Prime Minister within months to be interviewed by police as part of a sleaze inquiry.

The day-to-day inquiries will be led by Temporary Commander Nigel Mawer, working with officers from specialist and economic crime command.

Although there has not yet been a formal announcement of a criminal inquiry, Scotland Yard is expected to make an announcement today.

Harriet Harman, Labour’s deputy leader, who returned a £5,000 donation that was in breach of electoral law, is certain to be questioned. She claims she was unaware of the true origins of the money.

David Abrahams, the property developer who admitted concealing hundreds of thousands of pounds from the Electoral Commission, will be interviewed. Peter Watt, the Labour Party general secretary who resigned after admitting that he knew about the arrangement, will also be quizzed. Others, such as Jon Mendelsohn, Mr Brown’s fundraiser, and Hilary Benn, the Cabinet Minister who declined a hidden campaign donation, will be asked to help as witnesses.

Mr Brown has already admitted that the donations were illegal and has ordered them to be returned. He may be questioned because of claims that his campaign team unwittingly put Ms Harman’s office in touch with a proxy donor.

Sources confirmed that Mr Yates is to have a senior role with the investigative team. One said: “His experience is important. He knows how politics work, knows how Labour works and he has demonstrated that he is fearless and takes no nonsense.”

Mr Yates has been asked to oversee and advise the same team of officers that conducted the last investigation. It is understood that he was asked to lead the latest investigation, but declined because of other commitments.

Detectives were in talks with Crown Prosecution Service lawyers last night over how an investigation could be carried out. Their inquiries will centre on an alleged breach of the Political Parties, Elections and Referendums Act 2000, which stipulates that donors must be declared publicly.

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