A portrait to mark the selection of Britain's 'greatest national icon'

A photograph of Sir David Attenborough, shot to mark his status as Britain's "greatest living icon", is due to be unveiled at the Natural Portrait Gallery tomorrow.

The image is being displayed until the end of March to coincide with the showing of the last instalment of his Life in Cold Blood natural history television series.

The grandfather of nature programmes, who first appeared on television in 1954, was chosen as the top living icon in a poll organised by the Natural Portrait Gallery and BBC 2's The Culture Show.

Sir David, 81, beat Sir Paul McCartney and Morrissey after a 10-strong shortlist, including Alan Bennett and Kate Moss, was whittled down to three. The dramatically lit picture of an introspective-looking Sir David was taken at his home in Richmond, south-west London, by Richard Boll, the winner of the gallery's annual photographic portrait prize in 2006.

The photographer, who was commissioned to do the portrait as part of his prize, said he had wanted to show the serious side of his subject's character and reflect his dedication to the natural world.

This was suitably evident during the shoot last month when Sir David used every spare minute while adjustments were made to the lighting to hone the script for Life In Cold Blood, which brought the world of amphibians and reptiles to the screen.

Mr Boll said: "When you're producing a portrait that is as close up as this one, all the details of the expression count and consequently I took over 300 exposures to ensure I got what I wanted."

It is the third time that Sir David's image has been captured for posterity by the gallery. A portrait of him with his brother, Lord Attenborough, the film director, was completed in 1989 and an earlier photograph of him was commissioned in 1969.

A spokesman for the gallery, which will show the picture as part of its photograph of the month feature, said: "We think it is a very powerful portrait. We are very glad to have a contemporary photograph of Sir David to add to the collection."

The broadcaster declared himself happy with the new portrait, saying: "I haven't been shot so intensively since I was photographed for Madame Tussauds."

Although Sir David will no longer be making epic series, he will not be disappearing completely from the nation's television screens. He plans to make a few one-off programmes including a documentary on evolution.

Top 10 icons

*Sir David Attenborough

*Morrissey

*Sir Paul McCartney

*David Bowie

*Sir Michael Caine

*Stephen Fry

*Kate Bush

*Alan Bennett

*Kate Moss

*Dame Vivienne Westwood