Bring Me the Head of Thomas Baldwin

Tory sympathisers looking to dig dirt on Ed Miliband’s spin doctor, sources say.

Conservative Party supporters have "placed a bounty" on the head of Ed Miliband's spin doctor Tom Baldwin, following the resignation of the Downing Street communications directorAndy Coulson. According to senior Westminster sources, Tory sympathisers have employed the services of a private investigative agency to explore the background of Baldwin, who was appointed by the Labour leader last December.

Although the investigators were initially recruited prior to the announcement of Coulson's departure, the events of the past week have added to the determination to gather information that could embarrass Ed Miliband and senior members of his staff. "Before Coulson resigned it was business. Now it's personal," says another informed source.

The political stakes were ratcheted up in the hours following Coulson's resignation when Ed Miliband personally issued a series of statements criticising the wisdom of hiring the former News of the World editor. "I think it raises real questions about David Cameron's judgement that he hung on to Andy Coulson for as long as he did," he said. Those comments have reportedly given an added urgency to efforts to "throw the dirt back".

"Miliband was unwise to comment," said an observer. "The Tories are going to make it their mission to ensure his words come back to haunt him." There is no evidence that the decision to hire a team of private investigators was formally sanctioned by ministers or Conservative Party officials.

The former Times journalist has already been the subject of Westminster rumour following the publication by the Tory peer and donor Michael Ashcroft of the book Dirty Times, Dirty Politics, which made a series of allegations concerning his private life. Baldwin has never responded to the allegations, and they have never been substantiated. Again, there is no suggestion Ashcroft had any involvement in employing the investigators.

It's widely acknowledged that Baldwin's appointment, along with that of the former Daily Mirror political editor Bob Roberts, has given a significant boost to Ed Miliband's political operation. Since the turn of the year he has dominated the media agenda with a series of effective attacks on issues including VAT, bankers' bonuses and free book funding.

"Tom's landing blows and the Tories don't like it," says a Labour insider. "It's no surprise they're looking for ways to smear him."

It's also understood that Baldwin and Roberts are to prioritise closer co-ordination of the press operation of both Miliband and Ed Balls in the wake of the latter's promotion to shadow chancellor. Miliband's office is keen to avoid a repeat of the embarrassing policy splits and lax message discipline that characterised the relationship with Alan Johnson in the early months of the new leadership.

Balls will be moving his operation into a suite of offices adjacent to the leader, and is said to have agreed to a schedule of regular meetings between the two men. Although Johnson also had office space alongside Miliband's team, it was rarely used, and the former shadow chancellor admitted that meetings between the pair were infrequent.

Balls's well-respected press officer, Alex Belardinelli, will continue to represent his boss in his new role.