The National Portrait Gallery has unveiled its first painted portrait of former prime minister Tony Blair.

T he oil painting, which measures 4ft (1.2m) by 3ft (0.9m), is by artist Alastair Adams, who started work on it two years ago with several sittings at Mr Blair's home in Buckinghamshire.

Sarah Howgate, contemporary curator at the central London gallery, said: " The direct gaze of the sitter is uncompromising but also reflects his considerable skill as a negotiator on the world stage.

"The gallery is now able to represent Tony Blair with a portrait consonant with the personality of an individual who has considerably shaped the political, economic and cultural climate of Britain."

The gallery already has several photographic portraits of Mr Blair, including work by names including N ick Danziger, Terry O'Neill and Eamonn McCabe.

First elected as an MP in 1983, Mr Blair led his party to three general election victories and was prime minister for 10 years.