Westlife fans will be pleased to hear that the band are categorically not splitting up.

Westlife are currently working hard promoting their new single Tonight which is released on St Patrick's day (17th March, 2003) and are preparing for their Unbreakable world-tour which kicks off in Cardiff on 13th April.

Shane Filan told band members Kian Egan, Bryan McFadden, Nicky Byrne and Mark Feehily that if Anto weren't reinstated he'd quit.

But insiders say 22-year-old Kian - who masterminded the sacking - is refusing to budge, despite pleas from Shane and Bryan.

"Shane's not a happy man," our source insists. "He's told the rest of the lads that he's totally fed up.

"There were already simmering tensions in the band but when Anto was forced out, it was the last straw for Shane. He made his feelings clear at a showdown.

"And although they won't admit it in public, Shane has said that they've crossed the line and it's time to call it a day.

"There is a lot of animosity within the group now and morale is at an all-time low.

"When Shane walks out, they've lost their lead singer. It's like Boyzone without Ronan Keating - it just won't work."

"Everyone behind the scenes is working flat out to heal the rift."

Shane, who was allegedly offered a £6million solo deal last year, is considering going it alone. Meanwhile Bryan, 22, who has two daughters with wife, former Atomic Kitten star Kerry Katona, is also making plans for a back-up career.

The group have enjoyed incredible success since they burst on to the pop scene four years ago.

They have had an amazing 11 No1 singles and have sold 25 million records worldwide.

In December they surprised fans by releasing a greatest hits album but insisted they had no plans to go their separate ways.

"Best of" collections have been the death knell of many a pop act - remember Take That and Steps?

The lads are trying to paper over the cracks for their 32-date tour which starts in April and finishes in July.

A friend of Shane reveals: "He was incredibly angry about the whole thing and like many other people believes this is the beginning of the end.

"He loves all his band mates with all his heart but when fighting starts like this it's time to call it a day.

"He's had a few days to calm down now but he's still furious about the whole thing. It's not looking good."

There have even been suggestions that Westlife announce their break up officially after they play Dublin's Lansdowne Road stadium at the end of June.

"It would be the perfect time for them to bow out," says a pal. "But they're still hoping it's not too late to kiss and make up.

"But performing their biggest-ever shows at Lansdowne could be the big final curtain."