IT could be confusing, but UB40 are and are not playing Castle Howard on Sunday.

Legal requirements mean that the breakaway band formed by three ex-founding members in 2013 must bill themselves as UB40 Featuring Ali, Astro & Mickey, as in lead singer Ali Campbell, toaster, trumpeter and percussionist Astro and keyboard player Mickey Virtue.

Meanwhile, the band that can still call themselves UB40 – the one with five founders, Robin Campbell, Brian Travers, Jimmy Brown, Earl Falconer and Norman Hassan, plus long-time members Duncan Campbell, Martin Meredith, Lawrence Parry and Tony Mullings – will play York Barbican on April 26 next year on a 40-date tour to mark the Birmingham reggae veterans' 40th anniversary.

That UB40 have an album called For The Many on the way; UB40 Featuring Ali, Astro & Mickey released one in March: a set of reggae covers entitled A Real Labour Of Love.

The good news for UB40 fans is that both bands can play the mountain of hits the Birmingham brothers have piled up since debut double A-side King and Food For Thought reached number four in 1980.

What is clear is how much Ali, 59, still enjoys performing, whether in the Canaries, as was the case in April, or in the open-air at Castle Howard, near York, this weekend. "We just have to hope that when we come to Castle Howard the summer whether will be fine. It can be the difference between a great gig and a bad one," he says. Good news for Ali, the weather forecast predicts morning rain making way for a dry, mild afternoon and evening.

"We love doing the Routes of Kings shows, the woodland shows, and the racecourse, cricket ground and rugby ground shows we do for [promoter] Liz Hobbs," says Ali, whose band played Scarborough Open Air Theatre in June 2017.

Sunday's 26-song set will find room for three songs from A Real Labour Of Love, a return to the reggae covers albums that served UB40 so well. "We got as far as the Seventies on the third one and stopped there; we'd sold 21 million copies of those albums and a lot of people thought we'd become a covers band, but we've had 21 albums of our own songs, selling over 100 million copies," says Ali.

A Real Labour Of Love picks up the reggae thread in the 1980s and onwards to the 1990s. "The Eighties were really important for reggae because it went digital," says Ali. "Like we had to have a Beres Hammond song on there – She Loves Me Now – as he was the Otis Redding of reggae to me. We couldn't do a collection without Beres on there. He's a god in my eyes.

"We'll be doing that one at Castle Howard, and How Could I Leave by the Crown Prince of reggae, Dennis Brown, from The Seventies, and Astro will be doing Hard Times, originally done by Pablo Gad."

More songs from the album will only join the live set next year, once fans are familiar with the songs. "We're not self-indulgent; when you've done as many albums as we have, you can't go out and do songs live that people don't know,"reasons Ali.

Ali, Astro and Mickey are touring as a ten-piece, as they continue five years on the road, playing home and abroad, whether Castle Howard, Australia, New Zealand or California. "I'd say we're the hottest reggae band in the world at the moment, playing the biggest venues," says Ali.

You can sense his frustration when conversation turns to the rights to the UB40 name. "Originally I went out as 'Ali Campbell, the legendary voice of UB40', and did three albums that all went top ten," says Ali, who split from the original UB40 in 2008. "Then Astro came back into the fold with me, after the rest of them did a 'country album' and I thought, 'oh no, they're going to destroy the legacy'."

He goes on to call brother Robin's UB40 "the dark side", suggests "people are disappointed when me, Astro and Mickey are not there at their shows" and calls brother Duncan a "folk singer". "Duncan was a folk singer, our dad was a folk singer, and Duncan's not the person to sing my stuff. It's a slap in the face to me, who started the band," he says,

Against that backdrop, UB40 Featuring Ali, Astro & Mickey plough their own furrow, recording three albums so far . "Using that name, people know who's in our line-up," says Ali. "But nobody owns the name 'UB40'; it's a government name.

"They [Robin's band] don't have an impact on what we're doing, other than I'm highly embarrassed that people might think Duncan is me; that's the worst thing, thinking 'Ali's aged badly'!"

UB40 Featuring Ali, Astro & Mickey play Castle Howard, near York, on Sunday, supported by Aswad and Loose Ends featuring Carl McIntosh. Gates open at 5pm for a 6pm start. Box office: lphconcerts.co.uk or on the gate on the evening. Please note, this a non-picnic event.

Charles Hutchinson