Craig Bellamy's Newcastle future is hanging in the balance today after a training ground bust-up with manager Graeme Souness threatened to end his three-year stay at the club.

Souness addressed the media yesterday morning, demanding an end to Newcastle's culture of indiscipline and warning his players that their off-field indiscretions were preventing them from challenging for top honours.

Souness was angry that his side's preparations for tomorrow's UEFA Cup tie with Panionios had been overshadowed by the striker's latest display of petulance.

The Wales international was clearly seen to launch a volley of verbal abuse in his manager's direction when he was substituted in Sunday's 1-1 draw with Charlton and is also alleged to have made an obscene gesture in the direction of the home fans at the Valley.

Souness sought to discuss the matter with Bellamy on the training ground before the United squad boarded their plane for Athens yesterday.

But after the Wales international refused to be drawn into conversation, a physical altercation is alleged to have taken place.

Bellamy has been no stranger to controversy throughout his Newcastle career but, while Souness accepts he cannot rob him of his edge entirely, the 25-year-old is clearly living on borrowed time if he does not mend his ways.

This is not the first time a European trip has been overshadowed by his antics, as last season's UEFA Cup game in Real Mallorca became something of a sideshow after he hurled a chair at assistant manager John Carver in the airport departure lounge.

Bellamy also hit the headlines for the wrong reasons earlier this campaign when, following the 2-2 draw with Norwich, he warned he would leave St James' Park if Newcastle were successful in their bid to sign Wayne Rooney.

Souness had high-profile clashes with three other volatile players during his days at Blackburn Rovers, and it cannot have escaped Bellamy's attention that David Dunn, Andy Cole and Dwight Yorke were all forced out of the club after run-ins with the Scot.

"I'm angry about it all," said the Newcastle boss, before yesterday's ill-fated training session. "And the reason I'm angry about it is because we're talking about it.

"Instead of talking about how gritty and determined we were to get a point on Sunday, or how good a goal Craig Bellamy scored, we're talking about him for the wrong reasons.

"That has caused us to take our eye off the ball. There have been headlines about it in the newspapers today and yesterday."

Souness is probably unable to drop Bellamy as hamstring victim Patrick Kluivert has not travelled to Greece and fourth-choice striker Shola Ameobi is nursing a knock.