Jacques Santini last night threw Tottenham into early-season turmoil when the Frenchman resigned as manager, citing personal reasons, after only five months and 13 matches in charge at White Hart Lane.

His decision to quit is a massive blow to Spurs, who had begun the Premiership season well - albeit with a scarcity of goals - under the former France national coach. In recent weeks Santini's team slipped into the wrong half of the Premiership table after four defeats in five games.

Tottenham's assistant coach Martin Jol will take charge of the team for today's match at home to Charlton, and Spurs will make no further statement on the situation until Monday. The Dutchman will be seen as the favourite to succeed Santini on a full-time basis.

Santini said: "My time at Tottenham has been memorable, and it is with deep regret that I take my leave.

"Private issues in my personal life have arisen which caused my decision. I have therefore requested to return to France.

"I very much hope that the wonderful fans will respect my decision. I should like to thank (sporting director) Frank Arnesen and (chairman) Daniel Levy for their understanding. I wish the club and the supporters all the best for the season."

Arnesen said the club was disappointed with Santini's departure but understood his decision.

"We are obviously disappointed that Jacques is leaving us," said Arnesen. "We fully respect his decision. I can assure you that the club will act swiftly to minimise the impact of Jacques' departure. Our priority is to ensure that this season's performance remains unaffected by this move. We wish Jacques well."

Santini, who becomes the fifth Premiership managerial departure this season, has been recently been heavily criticised for employing negative tactics and only managed three league wins - and six goals, the Premiership's worst total - since he started working at White Hart Lane on July 1st after Euro 2004.

He blamed a number of injuries to midfielders and strikers for his side's recent decline, as well as tiredness among players, such as Robbie Keane, who had been performing regularly for both Tottenham and their countries. But there were also reports of unrest in the dressing-room and suggestion he did not know his best team.

On the personal front, earlier this season Santini revealed he was working so hard that he was still living out of a suitcase.

He said: "I am always working and I don't have Sky or anything in the hotel. I finish the day at 10 p.m. or 11 p.m. and I start at 7.0 a.m. This is all Tottenham.

"My wife and I do not have an apartment after two months here. We are still in a hotel, because I've not had the time to look for a house."

Meanwhile, Manchester United manager Alex Ferguson has hailed Roy Keane as the finest player of his 18 years at Old Trafford - and tipped the Irishman to be a managerial success in the future.

While Ferguson, who reaches the 18-year mark in the Old Trafford hotseat tomorrow, has seen the likes of Peter Schmeichel, Eric Cantona, David Beckham and Bryan Robson pass through during his time at United, the manager has no doubt Keane, bought from Nottingham Forest for £3 million in 1993, is the best of the lot.

"He is my best player," Ferguson said. "It's not just the quality of his game, it is also his influence and great determination. There are a lot of parts to making a great player - he has fulfilled them all."

Keane is currently attempting to gain his UEFA coaching badges, so he could enter the management arena if he wished to. And Ferguson feels if he follows that path, his captain will be a success.

"He is going in the right direction," said Ferguson. "You never know with the present day players because they are wealthy young men and they might not want to be managers. But if he has the desire, he certainly has the qualities."

Ferguson also admitted yesterday that his health rather than a desire to create a third great United side will be the factor that decides how long he stay on as United boss.

"It's difficult to say how long you can go on when you get to my age because you really are dependent on your health, but I feel good. I feel fit and fresh but you are never guaranteed your health when you get to 62-63," said Ferguson, who had a heart pacemaker fitted last year. "When I do pick a time to finish, it will be when I think it is right for the club itself and my health. I don't think the other issues come into it."