Bob Geldof has been threatened with legal action by ex-members of his old band the Boomtown Rats over alleged unpaid royalties.
The Boomtown Rats were a huge success in the 1970s and 80s
They claim he owes them money from the 1970s and 1980s, when the band had hits including I Don't Like Mondays.
Guitarist Gerry Cott, Simon Crowe, Garrick Roberts and John "Johnnie Fingers" Moylett have united to try to get the money they claim they are owed.
Geldof was unavailable to comment on Tuesday, his spokesman said.
The Boomtown Rats split in 1986, not long after they performed at Live Aid, which Geldof organised.
He is now involved in setting up the Live 8 shows to highlight global poverty.
In a statement released by Cott, who quit the band in 1981, they said: "We jointly confirm that with the utmost regret we are pressing ahead with our claims against Bob Geldof and others for our rightful entitlement to a proper share of recording, publishing and merchandising income.
''We have retained the London solicitor Angel and Co to act on our behalf and anticipate that proceedings will have to be issued shortly. We have no further comment at this stage."
They have also requested financial information from Universal Music - the record label which released a Boomtown Rats greatest hits compilation and re-mastered versions of their six studio albums earlier this year.
The Boomtown Rats scored 14 hit singles in the UK charts between 1977 and 1984 - including two number ones - and released five hit albums.
Geldof is credited as the sole writer on many of the band's songs.