The Buff Medways, Pleasure Unit, London

"To decide against your convictions is to be an unqualified and inexcusable traitor, both to yourself and to your country," wrote Mark Twain in Papers of the Adams Family. This sentiment sums up the ethos of another ritzily moustached patriot, "Wild" Billy Childish, who was on manoeuvres in Bethnal Green on New Year's Day with The Buff Medways, his small but tightly drilled platoon of reservist punk rockers. A totemic English eccentric, the 45-year-old musician, painter, poet and novelist is most famous for his ongoing spat with former lover Tracey Emin, his founding of the anti-Britart "Stuckist" movement and the regard in which he is held by a roll-call of rock and pop stars, including Kurt Cobain, The White Stripes, Andy Weatherall, Cornershop, P J Harvey and REM. His autobiographical novel, My Fault, is also an ongoing filmic work-in-progress for Kids director Larry Clark.

The Libertines' penchant for Crimean war uniforms, Estuary English Chas'n'Dave humour and shambolic saloon-bar confessionals can also be found in Childish's oeuvre.

2005 sees Childish adding to his body of 100-plus albums. One is of original songs, entitled Medway Wheelers, released on Graham Coxon's Transcopic label, and the other, The Genius of Billy Childish, has been culled from gigs performed between 1984 and 1993 with his two former bands, Thee Milkshakes and Thee Headcoats. This year also sees the publication of his third novel, Sex Crimes of the Futcher, a torrid account of the relationship between a painter, William Loveday, and Karima, a dark-haired fashion student from Margate - also described as "the Troll" - which may or may not be based on Childish's five-year romance with Emin, whom Childish met at Medway College of Art and Design, where she was studying fashion. A collectable painter in his own right, he has previously lambasted Emin as a "media whore", describing her artistic output as "shit". Emin, in turn, has threatened to bring in the lawyers if her name ever appears in any of his work.

But this performance is less about ire than about fun, as that fabulous walrus moustache hoves into view. The Kitchener-approved First World War apparel and the racket coming from the vintage equipment on the two openers - the Kinks' "Misty Water" and The Who-ish "Troubled Mind", from 2002's Steady the Buffs - recall Wilfred Owen's lines about "the monstrous anger of the guns... the stuttering rifles' rapid rattle". Drummer Wolf Howard is here disappointingly sans his trademark pickelhaube, but his drumming is louder than a self-propelled Howitzer.

The rough but thrilling awkwardness of the delivery, complete with the manly Cock-er-ney banter, is indeed "buff", as in deliberately amateurish and naked as Adam. It's the Buzzcocks in their birthday suits on the punky R&B of "Unable to See the Good" and "Nurse Julie" - from the last album, 1914 - and "You're Looking Fine", from Thee Headcoats' Headcoats Down!. Like a lusty general charging the Hun, Childish also tears through classics, such as Jimi Hendrix's "Fire", and ends with some Link Wray-style surfabilly that wouldn't sound out of place on Kill Bill Vol 3.

The star of the show, though, is that moustache - the kind that should have its own carriages and length of track. What a shame he turned down £20,000 to appear in Celebrity Big Brother.