Celtic coach Wim Jansen revealed in Estoril last night that he will give his decision on whether he stays with the Parkhead club or not before the week ends.

The speculation over Jansen's future has grown enormously in the build-up to the championship victory and now continues beyond it. Jansen said on Friday that he would speak to Celtic's chairman, Fergus McCann, and he would be the first to know whether Jansen would remain in the job or not.

However, strangely, with such a momentous decision being made, neither McCann, nor the club's general manager, Jock Brown, whose problems with the coach have surfaced over the past few months, are with the club in Portugal, where they will play a friendly against Sporting Club tomorrow night.

Celtic's players, meanwhile, were not so reticent, with Paul Lambert, Jackie McNamara, and Jonathan Gould joining assistant coach Murdo MacLeod in publicly calling for the Dutchman to stay on at Parkhead.

The team checked into their hotel, The Palacio, where the club based themselves before they won the European Cup by defeating Inter-Milan - the most memorable occasion in their history.

Now another memorable decision has been made. The man who delivered the championship after a decade of failure looks sure to leave.

Meanwhile, the men who might be able to persuade him to change his mind have not deigned to be here. Club spokesman Peter McLean explained: ''They have prior engagements.'' Surely, though, nothing should take priority over Jansen's future.

It becomes ever more clear that the coach will be leaving because of certain principles he holds dear. Yesterday, when I suggested to him that there had been inferences that he was ready to leave the club to go to a better paid job, he snapped: ''Anyone who tries to tell you that will not be telling you the truth.

''This has nothing to do with money. And, also, I have not spoken to any other club, or any agent about anything which concerns my position. Principles are important to me. When something becomes a matter of principle, then that is everything.

''I like to know the people I'm working for and I like to enjoy working with them. That is why the get-out clause was in the contract.

''If I don't know a club will like me, or I won't like a club, then I want to have the chance to leave. Maybe I am a little different from other people. Also, it won't bother me if I take a break. I have done this before - that is my way.''

Jansen has clearly been gratified by the tide of emotion that has swept towards him from the Celtic support, who have seen the cherished championship delivered at last. He admits: ''Obviously I was affected by the emotion after the game.

''Anyone would have been affected. I know how much it meant to the support. I know just how long they have waited for this moment, but I cannot allow that to affect my decision. I had made my decision already before the game.

''Yes, it was difficult, but any decision you make is difficult. Decisions can be very difficult, but always you have to make them away from the emotions.

''Even coming to Celtic was a hard choice for me. I'd been told by people in football the problems which existed.

''I'd been told about the nine in a row that Rangers had won and the problems of stopping them and I knew that changes had to be made, but I took the chance.''

When he did so, it is doubtful that he realised just how serious the club's position was.

He admits: ''We had to change things gradually. I kept telling my players that it was not just about winning the games against Rangers. To win the championship, we had to win games against other teams.

''In fact, this time in the league you see that Rangers lost their championship because they lost the matches against the other sides. I had to keep impressing this on my players.'' Jansen's strategy worked. His players picked up points as Rangers lost them and, at the weekend, he was able to take them to the title.

In doing so, Jansen has impressed his players, with Lambert, who last season won the European Cup with Borussia Dortmund, for example, rating the Dutchman as the best manager for whom he has worked. The players are unanimous in suggesting that adapting to a new coach would not be ideal preparation for their own Champions' League campaign.

Now, however, as much as Janson savours the title moment - and he does, make no mistake of that - he knows that his future seems sure to be elsewhere.

Only his wife shares the secret of the decision that has been made. However, those close to him at the club believe that Jansen, this man of principle, will walk away from this latest success.

I believe that to be the case and so Celtic will once again be in a state of flux during their celebratory summer. A new coach must be found, someone to carry on where Jansen's work has stopped - and someone who must bow to the strictures that come down from on high at Parkhead.

That is something Jansen would not do.