They have spent the past three decades advocating the virtues of love, relationships and the sweeter things in life through their feel-good reggae music. But the spirit of UB40, one of the most successful British bands, has been soured by an acrimonious split that has pitted brother against brother.

On the eve of their latest world tour Ali Campbell, the frontman, walked away from the group with a parting shot at his older brother, Robin, the lead guitarist.

The remaining members of the band told The Times of their shock and disappointment at his behaviour, complaining that he had used a solicitor to announce his departure.

James Brown, the drummer, said: “You would think after 30 years of working together as a family unit that you could at least have talked through these issues.”

Campbell, 48, cited intolerable management difficulties when he quit last week because of a dispute with DEP International, the band’s label, over financial issues. He was incensed further by the official explanation from the band that he had left to concentrate on his solo career.

He said: “Robin has just gone and thrown a jealous hissy fit and sided with the management against me. The idea that I’ve left the band because I want to concentrate on my solo career is absolute nonsense.

“The truth is that was nothing but a nasty bit of spin put out by the management because they know I’ve been making life difficult for them recently by asking them the questions they didn’t want to be asked.”

Campbell had hired a team of investigators in an attempt to gain access to the group’s millions, which he claims he has been frozen out of. He said: “It has been like opening a bank account, putting all of your money in there, then asking to see the account and the bank refusing you permission.”

The other members insisted that they and Campbell had made all creative and financial decisions together.

A spokesman said: “Ali seems to have forgotten that he has at all times been involved in this process. It’s also somewhat puzzling that the other members don’t have any issues over any decisions.

“Ali made a very simple decision: he chose to pursue and put his solo career over and above continuing to work with UB40.” Campbell complained that only Sir Paul McCartney phoned to offer congratulations on the success of Running Free, his solo album, when it was released last October. “Not even Robin bothered to phone and congratulate me,” he said.

The group told The Times that they had delayed the release of their album until May so Campbell could promote Running Free. Their spokesman said that they were disappointed that despite this support Campbell did not commit fully to tour dates for this year. He will perform with UB40 in Australia, New Zealand and Uganda next month but will pull out of the rest of the tour. The band have not decided whether to replace him.

The acrimony marks the end of an era for the Birmingham-based group, who have sold 70 million albums worldwide and achieved three number one singles, for Red Red Wine, I Got You Babe and (I Can’t Help) Falling In Love With You. Campbell is the only member of the original line-up to quit the band.

In an interview in 2005, Robin attributed the success of the group — named after an unemployment form — to the friendship shared by all its members. “We all know how lucky we are together,” he said at the time. “If anyone gets out of control the rest of us reel them in.”

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