Manchester United today re-entered negotiations with Wayne Rooney's agent, Paul Stretford, on a day when the outrage felt by the club's supporters escalated into militant action and chilling threats.

While Rooney was pondering the fall-out from several hours of high-level talks at Old Trafford, a 40-strong group of United supporters, many wearing balaclavas and hooded tops, had travelled to his home in Prestbury, Cheshire to warn him off any move to Manchester City. Witnesses reported a gathering outside his house, with a banner reading "If you join City you're dead".

The incident occurred a couple of hours after United released a statement confirming they had spent the day discussing Rooney's future. The club's chief executive, David Gill, spoke to Stretford to reiterate Sir Alex Ferguson's belief that the player could be on the verge of making the biggest mistake of his professional life.

City are willing to pay Rooney £260,000 a week, which would make him the highest-paid player in the Premier League, but there is a desire among senior figures at Old Trafford to keep him. The fact he was not transfer-listed today suggests at least that there are attempts behind the scenes to resolve the matter. Gill had an hour-long meeting with Ferguson at lunchtime and spoke to the club's owners, the Glazer family, by telephone.

Rooney's position had begun to look untenable when he released a statement on Wednesday confirming that he wanted to leave Old Trafford, citing a concern that the club were in danger of stagnating at a time when they no longer appear to be in a position to sign the more expensive players on the market.

Ferguson had responded by saying his priority was to "put it to bed" today. The manager is known to be frustrated that he has been unable to do so, believing the ongoing drama could have an adverse effect on his other players before Sunday's game against Stoke City.

The only public comment from Old Trafford was a statement from Gill to confirm that more talks were planned and to ask supporters to show understanding.

"We are aware there is intense public and media interest on the club at the moment," Gill said. "I can confirm a number of meetings have taken place today, including with the player's representative. The outcome of those meetings will become clear in the near future. In the meantime fans are asked to be patient."

United are aware of the growing swell of opinion against Rooney from supporters and the player is said to have been dismayed, though not entirely surprised, by the reaction at yesterday's match. The depth of anger against Rooney manifested itself during the game against Bursaspor when supporters held up banners castigating his behaviour.

The demonstration at his house had a much more sinister edge. In 2005 Rio Ferdinand faced a similar visit from a mob of balaclava-wearing men dressed predominantly in black, because of a 16-month contract dispute during which he had been photographed with the then Chelsea chief executive, Peter Kenyon.

Ferdinand went to his front door to confront the fans and answer their questions during a tense standoff, the defender admitting in his autobiography that he had feared for his own safety. The same people are believed to have been involved last night in what seems to amount to a determined attempt to intimidate Rooney out of a move to Eastlands. There was no direct confrontation, however, at the house. Police were called to the address at around 8.30pm although no arrests were made.

Rooney has also put himself in a difficult position with several team-mates with his statement that the main reason he wanted to leave was because of his concerns that United might not be in a position to challenge regularly for trophies. The clear implication of his behaviour is that he believes United are in danger of slipping behind more powerful spenders, specifically Chelsea and Manchester City, as well as major forces in Europe such as Milan, Real Madrid and Barcelona.

City are continuing to monitor his potential availability with a view to signing him in the January transfer window. Though Real Madrid's president, Florentino Pérez, has made no secret of his admiration for the striker, there is a feeling at the Bernabéu that another club is ahead of them.

Rooney is said to favour staying in England, not least because his wife, Colleen, places great emphasis on helping to care for her younger sister, Rosie, who suffers from the brain disorder Rett syndrome. Stretford also has a long association with Brian Marwood, the man charged with negotiating new signings for City in his role as the club's football administrator.