STEVE McClaren last night claimed that, by signing a new four-year deal, he had underlined his "whole-hearted commitment" to Middlesbrough.

But, despite pledging himself to the Teessiders until 2009, neither the Middlesbrough manager nor his chairman, Steve Gibson, would rule out the possibility of him eventually leaving to lead England.

After verbally agreeing the terms of his new contract in the summer, McClaren finally put pen to paper yesterday morning in an attempt to quell mounting speculation over his future.

With Sven Goran Eriksson expected to leave his post as England manager in the wake of next summer's World Cup finals, the Boro boss has been widely touted as one of his most likely successors.

That remains a possibility but, with the new deal containing no get-out clauses or agreements for compensation, Gibson has given himself every chance of holding onto the most successful manager in his club's history.

McClaren has consistently played down talk of leaving the Riverside and, sitting alongside his chairman, the 44-year-old claimed his extended contract provided irrefutable proof of his devotion to Middlesbrough.

"I really want to get across the message of how committed I am to this football club," said McClaren, who also revealed he had discussed the possibility of making further signings in January when he spoke with Gibson earlier this week. "That's why I've signed again.

"We've had four years together and they've been four successful years.

"I asked the chairman what he wanted to achieve in the next four years and our ambitions matched each other's. That's why I've signed.

"This is my commitment to the club, the players and the fans. My concern at the present moment, and for the next four years, is to bring more success to Middlesbrough."

Middlesbrough have vied with England for McClaren's attention since he took over at the Riverside in June 2001.

The former Manchester United assistant was at Eriksson's right hand man when the Swede took charge of the national side and, while he had relinquished his duties by the time he left Old Trafford, he returned to the England set-up for the 2002 World Cup.

He was back alongside Eriksson during last summer's European Championships and will be a prominent member of the backroom staff when England travel to Germany for next summer's finals.

No matter what his new contract is supposed to signify, it is only a small step from there to the top job and, while careful to constantly commit himself to Middlesbrough, McClaren is unable to hide his longer-term ambitions.

"It must be everyone's ambition to either play for their country or manage it," he said. "I'm no different to anyone else but, ultimately, Sven is in the job and the job is not there.

"There is no mention of England (in the contract) whatsoever. There's been a lot of speculation and I'm flattered by all the interest.

"But Sven is doing a fantastic job and he's contracted to 2008. I've signed this contract to show my commitment. Over the next four years, my sole ambitions lie with Middlesbrough Football Club. I want to achieve more success here."

That is as maybe, but even Gibson has been forced to accept the reality of the situation.

The Boro chief has seen his club win their first major trophy, record their highest Premiership finish and play in their first European campaign under McClaren's control and he did not hesitate to offer his manager a new deal.

He fully expects the Yorkshireman to enjoy more success in the future, but admits he would be powerless to prevent him upping sticks if the FA were to make an offer he could not refuse.

"One day, I want Steve McClaren to be the manager of England," said Gibson. "But only when the time is right for him and he will know when that is.

"I'm a realist and, if you're given the opportunity to lead your country in any sport, you almost have a duty to take it on.

"While I wouldn't encourage Steve to do it because my first priority is with Middlesbrough, neither would I stand in his way.

"I wouldn't deny any man the right to lead his country. If we get to that point, I'll be delighted for Steve, I'll be delighted for me and I'll be delighted for this football club.

"But that's all hypothetical at the moment. Steve is now part of the fabric of this football club and I think we're getting into his fabric as well.

"Middlesbrough is very much a part of Steve McClaren.

"I think the next four years could be even better than the last four years. I'm sure the most exciting times are in front of us."

McClaren clearly shares that vision. Despite his side currently languishing in the bottom half of the Premiership, he remains confident of recovering from an inconsistent start.

Tomorrow's trip to Alkmaar offers the prospect of qualification for the UEFA Cup group stage and, ultimately, it is the Champions League that increasingly dominates his thoughts.

"Over the next four years, our ambitions are to be in contention for a trophy and in contention for Europe every season," said McClaren, who has elevated former attacking coach Steve Round to the position of assistant manager and appointed Colin Murphy as head of recruitment.

"Beyond that, I would love, even just for one season of the four, to be in contention for a Champions League place. I feel that is achievable.

"There's still plenty more for us to achieve. We've built a platform, but the challenge now is to build the stepping stones to greater success."

* UEFA's disciplinary committee will meet this morning to discuss Abel Xavier's failed drugs test.

The Boro defender tested positive for the anabolic steroid Dianabol following September's UEFA Cup game in Xanthi and is expected to receive a one-year ban if the offence is upheld.

Middlesbrough officials have always adopted a 'no tolerance' policy to drugs and will sever Xavier's contract if he is found guilty.

Read more about Middlesbrough here.