In 1984 he became art critic of the
Evening Standard (replacing avant-garde critic Richard Cork). He won press awards including Critic of the Year in 1988, Arts Journalist of the Year in 1994, the Hawthornden Prize for Art Criticism in 1995 and the Foreign Press Award (Arts) in 2000. In April 2003 he was awarded "The George Orwell" prize for his political/current affairs column in the
Evening Standard. In criticisms of the Tate Gallery's art, he coined the phrase, the "Serota Tendency", after its director Nicholas Serota. It was not until the late 1990s that he became a household figure through television, though he was on BBC Radio 4 before then.
Sewell is noted for formal, old-fashioned diction and anti-populist sentiments. He offended people in Gateshead by claiming an exhibition was too important to be held only at the town's Baltic Centre for Contemporary Art and should be shown to "more sophisticated" audiences in London; he has also disparaged Liverpool as a cultural city.
In 1994, 35 art world signatories wrote a letter to the
Evening Standard attacking Sewell for "homophobia", "misogyny", "demagogy", "hypocrisy", "artistic prejudice", "formulaic insults and predictable scurrility". Signatories included Karsten Schubert, Maureen Paley, Michael Craig-Martin, Angela and Matthew Flowers, Professor Christopher Frayling, Rene Gimpel, Susan Hiller, John Hoyland, Sarah Kent, Nicholas Logsdail, George Melly, Sandy Nairne, Sir Eduardo Paolozzi, Bridget Riley, Michelle Roberts, Richard Shone, Marina Warner, Natalie Wheen, and Rachel Whiteread. He responded with comments on many of the signatories, saying that Paley was "The curatrix of innumerable silly little Arts Council exhibitions", and that Whiteread was "Mortified by my dismissal of her work for the Turner Prize". A letter supporting Sewell from 20 other art world signatories accused the writers of attempted censorship to promote "a relentless programme of neo-conceptual art in all the main London venues".
Sewell's attitude to female artists has been controversial. In July 2008 he was quoted in
The Independent as saying:
"The art market is not sexist. The likes of Bridget Riley and Louise Bourgeois are of the second and third rank. There has never been a first-rank woman artist. Only men are capable of aesthetic greatness. Women make up 50 per cent or more of classes at art school. Yet they fade away in their late 20s or 30s. Maybe it's something to do with bearing children."
Sewell does not hold his tongue regarding his opinions, and has frequently insulted the general public for their views on art. Consequently, he is more known for controversy than art criticism among many. He has issued quotes such as the following regarding public praise for the work of Banksy in Bristol:
"The public doesn't know good from bad. For this city to be guided by the opinion of people who don't know anything about art is lunacy. It doesn't matter if they [the public] like it."
He went on to assert that Banksy himself "should have been put down at birth."Clive Anderson has described him as "a man intent on keeping his Christmas card list nice and short."
Sewell is also known for his disdain for Damien Hirst, describing him as "fucking dreadful."