Satirist John Wells, best known for his caricatures of Denis Thatcher and his leading role in the success of Private Eye magazine, died yesterday from cancer. He was 61.

Wells, who co-wrote with Richard Ingrams the Eye's Dear Bill letters and also portrayed former Prime Minister Margaret Thatcher's husband on stage and TV, was first diagnosed with lymphoma more than a decade ago.

However, he appeared at one stage to have overcome the disease.

His brother-in-law, the journalist Alexander Chancellor, said that Wells died at his home in Kensington, west London, at about 8am yesterday.

''He had been in remission, but then it came back with a vengeance last year,'' added Mr Chancellor.

The only child of a dean from Bognor Regis in Sussex, Wells first achieved fame as a student at Oxford University, appearing in Late Night Final at the Edinburgh Festival.

He then became a schoolmaster at Eton, teaching French and German. But the lure of the stage was too strong for him and he began to move away from teaching in 1962 when he appeared in a cabaret with Barbara Windsor.

An all-round humorist, Wells - who listed his recreations in Who's Who simply as ''walking, talking'' - was also one of the original writers for Private Eye when it was launched in 1961.

Indeed, it was with the Eye column Mrs Wilson's Diary, detailing the fictional life of the wife of the then Prime Minister Harold Wilson and co-written with Ingrams, that Wells was initially most associated.

He repeated that success in the 1980s with the Dear Bill letters, chronicling Margaret Thatcher's Premiership through the eyes of her husband.

The letters, purportedly written to the veteran journalist W F Deedes, lampooned Mr Thatcher as a gin-swilling reactionary interested in little other than golf and his next ''snort''.

Wells built on that success by portraying Denis Thatcher on both the stage, in his play Anyone For Denis?, and on TV, in each case looking alarmingly like the original.

However, Wells himself was ambivalent about the huge popularity of Anyone For Denis? and the Dear Bill letters, once claiming that he had done more than the Prime Minister's own image-makers to endear the Thatchers to the British public.

''Saatchi & Saatchi advised Mrs Thatcher to see Anyone For Denis?. She hated it,'' said Wells in 1983.

''The press made out that she was a bending person able to laugh at herself. In fact she is totally incapable of that.

''After seeing the play she managed to hiss 'a marvellous farce' through gritted teeth.''

However, yesterday Baroness Thatcher paid tribute to the humorist.

On being told of his death by PA News, she said: ''I am so sad. He brightened up our lives so much.''

Asked about her celebrated viewing of Anyone For Denis? - and whether she had been able to share in its humour - she added simply: ''We enjoyed it very much.''

Richard Ingrams, former editor of Private Eye, also paid tribute to the satirist, whom he first met at Oxford some 40 years ago.

''He had the reputation then of being a brilliant cabaret artist, very, very good at doing impressions of people, but he was also a very sharp writer,'' said Mr Ingrams.

''I remember particularly writing the Dear Bill letters with him. He was a very easy person to work with and we always wrote them very quickly. It was really the most successful feature that Private Eye ever had.

''In addition to his satirical work he also did a lot of serious stuff. He wrote plays and was a very good translator.''

That serious work included opera, with Wells translating The Marriage of Figaro and The Barber of Seville into English as well as directing a production of The Mikado.

Wells himself once said: ''I still have a puritan belief that, if I've been enjoying myself too much, then it's time to go off and translate an obscure German play somewhere.''

Nevertheless, it is as a satirist that Wells, who is survived by his wife Teresa, 62, and the couple's daughter Dolly, 25, will be best remembered.