David Hockney.

" David Hockney and one of his most consistent models Celia Birtwell were reunited in front of his most famous painting ...to mark the opening of the first major survey of his portraits. Mr and Mrs Clark and Percy features Birtwell and her then husband Ossie Clark and a cat called Blanche (Hockney preferred the name Percy) as an embodiment of swinging London. The work was the only one by a living artist to be named in a poll of the nations favourite paintings last year."