The gathering of signatures for a letter of complaint to Mr Sewell's employer has taken weeks, from writers, dealers, artists, some of them victims of Mr Sewell's pen. Eduardo Paolozzi is a signatory, for example. Has he been rude about him? 'Of course,' said Brian Sewell, disdainfully. 'Anyone who makes such a fuck-up of decorating an underground station . . .' Rachel Whiteread is another signatory: Mr Sewell has described her Room wittily, if a little harshly, as 'another Whiteread sepulchre, cast in plaster . . . a surreal whimsy that grows thin with repetition . . .' In his review of 'Writing on the Wall' - an exhibition of women's art from the Tate's own collection chosen by women writers - which seems to have been the final straw, Mr Sewell made reference to 'the hysterical rantings of blind women critics on Kaleidoscope'. Natalie Wheen, a radio critic, has signed the letter, too.
Victims of myriad stings, these objects of his past attacks and their friends and sympathisers, have risen at last and let the poison out. They have accused Mr Sewell principally of political incorrectness: homophobia, misogyny and, more mysteriously, 'class hypocrisy'.
Could his accusers mean that Mr Sewell has betrayed his educated upper-middle-class connections (he was once close to Anthony Blunt) in his contempt for upside-down Christmas trees and piles of marble eggs? It is Mr Sewell's view that the approach of people who produce and promote incomprehensible works of neo-conceptualism is elitist. 'The one thing they can say about Brian is, he's a little perfumed,' said Roy Miles, gallery owner, who has risen to Brian Sewell's public defence. 'We've had about 50 calls of support since I wrote to say he was right. My taxi driver said on the way home, 'I do agree with your letter'.'
At the Tate this week, in the centre of the room in which 'Writing on the Wall' is displayed, a man sat, gazing at a large canvas of a dying horse. At a distance he seemed entranced. Closer, it became clear that he had simply glazed over. 'Don't ask me what I think,' he said sadly. He was, he said, just an ordinary person. 'I don't understand this. My opinion is worth nothing.' I coaxed him a little. 'Most of them are a bit depressing, aren't they?' he ventured.
This summed up Mr Sewell's view on this exhibition perfectly. 'A show defiled by feminist claptrap,' he wrote, and, of Vanessa Bell's nude: 'It could hardly be the favourite of even a purblind lesbian.' His main objection is to the idea of choosing work because it is done by women, rather than because it is the best of its kind. This may be an old-fashioned point of view, but it is, surely, even in these days, not misogyny? The show displays work chosen by women writers. Mr Sewell liked the poem Wendy Cope had written to go with the Bell. He praised Grace Nichols's writing as 'formidable wisdom' and the landscape by Sheila Fell, one of whose paintings he owns.
Marina Warner, an arts writer, signed the letter after having it read to her by Natalie Wheen and being faxed his piece on the exhibition. She is not impressed by Mr Sewell's recommendation of particular women. 'If you sneer at women as a group, and make exceptions because these are nice or toeing the line or something, if you dump on women as a group you legitimise the Government in its particular trend of hypocrisy (ie, she explained, its attitude to single mothers).' But would Timothy Yeo have been helped by attending the Tate? Would he have understood 'Writing on the Wall'? The viewers were having some problems. Close to Vanessa Bell's landscape a woman fumbled with a perspex case, trying to extract a leaflet explaining the purpose of the show. She failed.
Mr Sewell, in his trenchant manner, pointed out that unless the prose or poems are pinned up near the pictures the whole show looks, to the ordinary viewer, like a random jumble. He is right. After five minutes, the ordinary man in the middle got up and took a closer look. He came over to give me a more considered opinion: 'Some of the frames are nice.'
Glenys Baker, a tourist from Adelaide, also looked weary. 'I liked the Blake, the Impressionists, the Surrealists are interesting - but when they get to what they call painterly stuff that's when I sort of turn off,' she said. 'I can't work out why they're wasting the space. Do you know what it means?' It was a genuine, baffled plea.
Back in the Tate's hall, two tourists discovered that they, too, were walking over Carl Andre's minimalist tiles and burst into giggles. Brian Sewell may be, like the Prince of Wales on the subject of Sixties architecture, an odd representative for the man on the street. Certainly he is sometimes offensive, predictable, and generally rubbishing in tone. So, very noticeably, is the letter which attacks him. But at his worst Brian Sewell, at least, knows how to make himself understood.