Tate Modern spectacular: The Gilbert and George show

After a 40-year career dogged by controversy, Britain's best-known artistic duo are to be given their first major retrospective

They were the enfants terribles of British art when Damien Hirst was still a baby and have established an international reputation over nearly 40 years, but Gilbert and George still had to spend five years lobbying for what should be the crowning glory of their career so far - the biggest show Tate Modern has dedicated to a "single" artist.

They rejected an original offer of a show at Tate Britain. "I think we're modern artists rather than British and the space was more suitable for our exhibition as well," George said. "And I'm not British," added Gilbert, who still bears the inflection of his native Italian.

Tate eventually agreed to the show the artists wanted. And in one of their favourite East End restaurants yesterday, the two men were on hand as the gallery announced details of what will be the first major retrospective of their work for a quarter of a century. The exhibition will include more than 200 pictures from the past 35 years, the most extensive survey of their work so far mounted.

It will occupy the east and west wings of Tate Modern's level four and will include a new piece the artists are creating for the concourse. "You won't like it," Gilbert said, when asked for details.

George, who was born George Passmore in Plymouth in 1942, said it was the ideal time to mount the show. "We said, 'Goody, goody! At last.' A retrospective of work is so rare. Half the people who saw the [Whitechapel mid-career retrospective] in 1981 are dead. Half the people who will see the exhibition weren't alive when the Whitechapel showed us. It's not like football or tennis or going to the cinema. It's a very rare thing."

Jan Debbaut, the former director of Tate Collections who is returning to curate the show, said there had been only four major institutional exhibitions of the artists' work in their career and the retrospective was "long over-due". Gilbert and George were "living sculptures," he said, who were among the best-known artists in Britain.

Gilbert Proesch, who was born in Italy 63 years ago next week, met George in 1967 when they were students at the St Martin's School of Art and they began working together. Famed for looking dapper in defiance of more bohemian modes of dress, their work has often seemed scandalously at odds with their respectful besuited appearance.

The artists have provoked controversy with depictions of sexual acts and bodily fluids, often produced in sequences. When the National Portrait Gallery acquired their self-portrait, they became the first full-frontal nudes in its collection.

Despite winning the Turner Prize in 1986 and representing Britain at the Venice Biennale last year, the pair have often lamented their general exclusion from the national collections. "In the last 20 to 30 years we never saw a piece of our work at the Tate. We don't know why," Gilbert said.

Everyone was keen to extend a welcome yesterday. Vicente Todoli, director of Tate Modern, said: "We're delighted to be mounting this exhibition." It was all gratifying to the artists. "Everybody used to say, 'Gilbert and George, very interesting, but will it last?'" Gilbert recalled. It did.

Gilbert and George runs at Tate Modern from 15 February to 7 May and will then travel to Germany, Italy and America.