IF Britain is ever truly to take its rightful place at the heart of Europe, we're going to need a lot more entertainment options that begin after 11 o'clock. Brixton's Late Lock-In is a bold step in the right direction. This appetising smorgasbord of after-hours character comedy is newly established on the fifth floor of The Brix - a derelict church converted into a thriving fun palace - with the bump and thump from the nightclub across the corridor offering a piquant reminder to comedy followers of how more successful people spend their Friday nights.

Genial landlord Al Murray is the perfect host. A familiar figure to all those lucky enough to have experienced Harry Hill's 1994 Pub Internationale show, Murray is the proud possessor of a catch phrase - "I'm not saying it's right, I'm not saying it's wrong, it's just the way things are" - worthy of Judas Iscariot. The warmth of his welcome is genuine, and the sensitivity with which he handles the potentially troublesome Gayle Tuesday, Page 3 Stunna, is much to be commended.

The Late Lock-In's great innovation is its potential for spontaneous interaction between well-established comic characters: cf. when Murray's courtly pub-speak collides with the impassioned street rhetoric of Alan Parker, Urban Warrior: "Don't call me squire - I'm an ordinary decent mem- ber of the urban proletariat." Parker's alter ego, Simon Munnery, is revered by other comics as a rare and genuinely dangerous talent, so in some ways it is odd that he has persisted for so long with such a non-toxic character; but a TV pilot beckons at last, and lines such as "The Birmingham Six are free - when will the rest of Birmingham be free?" are probably their own reward.

The sinister innuendoes of Matt Lucas's Sir Bernard Chumley just get better with age. You'd think the one about entering the Young Musician of the Year would start to pall on fourth or fifth hearing, but it doesn't. And some of his running gags - "Shabba Ranks ... funny he never married" - are starting to take on a life of their own. It would be a shame, though, if Lucas, who's still only just the wrong side of 20, got trapped in the guise of the Touretting thespian, so his new character - a cockney in mortal anguish - is a very welcome sight.

Australia's Umbilical Brothers - currently at the Arts Theatre in a delayed but highly polished transfer from last year's Edinburgh Festival - live at the opposite end of Comedy Avenue to the Late Lock-In posse. As innocents abroad in a world of high-octane slapstick, David Collins and Shane Dundas inhabit the same basic territory (Harold Lloyd with added sound effects) as fellow Antipodeans and 1994 Perrier Award-winners Lano & Woodley, but to considerably less irritating effect. As the collected speeches of Sebastian Coe so poignantly testify, physical and mental agility are often reluctant bedfellows, but in this case brain and brawn prove pleasingly compatible.

A step on the stage becomes a perilous high-rise window ledge, a plastic dinosaur pursues an astronaut, and hands multiply like fruit-flies. In fact there are almost enough visual coups in the act to enable the audience to forgive the Brothers for wearing braces over red T-shirts. The false beginning, though, is another matter. A false beginning is something that can never be forgiven. Like people whomake models of the Houses of Parliament entirely out of used cotton buds, the Umbilical Brothers should be congratulated on their dex- terity, but dissuaded from run- ning for major political office.

The Late Lock-In: The Brix, SW9 (0171 274 6470), last Friday of every month. The Umbilical Brothers: Arts Theatre WC2 (0171 836 2132), Mon to Sat to 16 Mar.