When M People's Elegant Slumming trounced the cream of Britpop to win the 1994 Mercury music prize, their multimillion-selling aspirational anthems captured the positivity of the 90s. New Labour rose to power in 1997 to the strains of Moving On Up ("Nothing can stop us"). But in today's climate of economic gloom and social hardship, the band's ambitious 20th-anniversary hometown comeback has produced a quarter-full arena.

"Come on Manchester," yells big-lunged singer Heather Small, perhaps feeling like she is trying to push a boulder up a hill. It certainly takes some chutzpah to sing One Night in Heaven in front of black curtains concealing empty seats.

It's not just the sentiment of the songs (lots of advertising-type platitudes about "respecting yourself" and "the strong survive") that sounds badly dated; the music does, too. Twenty years ago, former Hacienda DJ and Factory Records artist Mike Pickering's band sold a diet version of club culture to mainstream punters. But Italian house-style pianos and lite club grooves haven't been pop staples for years.

Without enough hits to carry off a two-hour arena show, the set has more padding than a soft furnishings outlet. There are percussive workouts, extended sections, saxophone over everything and at one point Small actually yells "Are you still there?" into the mostly quiet audience. A particularly baffling jazzy fusion jam – performed while the singer changes from a red dress into a glitter suit – could convince even the most committed fan that they've arrived at the wrong gig.

The hits – especially Moving On Up – get the faithful on their feet. Small sings Search for the Hero ("inside yourself") with impressive gusto, perhaps because she's spent the last two hours doing exactly that.