Manchester United manager Sir Alex Ferguson has no time for retirement talk after beating Sir Matt Busby's record

The Manchester United manager, who celebrates his 69th birthday on New Year’s Eve, eclipsed Busby’s 8,810 days service as United manager on Sunday. And Ferguson will mark 25 years at Old Trafford if he continues to be in the charge of the club next season.

Having changed his mind on plans to retire at the end of the 2001-02 season, Ferguson has since claimed that he would not work beyond his 70th birthday. But with United now chasing a record 19th league title, the Scot admits that he has no idea of when he might call time on his management career. Ferguson said: “The older you get, the more worried you are about retiring. “You start to realise that, whilst you have got your health and good fitness, you should carry on in your job. All thoughts of retirement are in the back of my mind.

He described the decision to say he was going to go as “a mistake”, adding: “At the time there were some reasons for it. It was one of those things.”

United missed out on the chance to extend their lead at the top of the table following the postponement of Sunday’s clash with Premier League champions Chelsea at Stamford Bridge.

But despite the growing threat from across Manchester in the shape of Roberto Mancini’s high-flying City team, Ferguson believes that Tottenham – who entertain United at White Hart Lane next month – can also challenge for the title this season.

He said: “It is a tough league, but do you want Manchester United and Chelsea or Arsenal to steamroller the league every season? “I think the public like what they’re seeing now, all of us dropping points, and you have also got the rise of Spurs.

“They have been fantastic since Harry [Redknapp] went there. They could have won some games and could have lost others, but there has been a real improvement by them. “As Harry says, why can’t they win the league? That is getting through to his players.”