Amanda Smith at Vincent Avenue by Simon Davis. © Simon Davis

Four artists have been short-listed for the BP Portrait Award 2008, which has this year attracted record numbers of entries from non-UK artists and those over the age of 40.

For the second year running, the competiton, which is held at the National Portrait Gallery in London, has been open to all over the age of 18, and of the 1,727 entries 780 (45%) were from artists aged 40 or over. 536 entries (31% of the total) came from outside the UK.

55 portraits - 38 from the UK and 17 from abroad - have been selected for the exhibition which runs at the National Portrait Gallery from June 12 to September 14.

Hannah O'Brien by Robert O'Brien. © Robert O'Brien

Sandy Nairne, Director of the National Portrait Gallery, said: "The entry to the 2008 BP Portrait Award was of the highest standard and included every kind of style. Painted portraiture is thriving."

The four artists shortlisted for the 2008 award are: Simon Davis for Portrait of Amanda Smith at Vincent Avenue; Peiyuan Jiang for Untitled; Robert O'Brien for Hannah O'Brien and Craig Wylie for K.

In addition to a cash prize of £25,000, the winner will receive a commission worth £4,000. The second prize will be £8,000 and third £6,000.

There is, also for the second time, a BP Young Artist Award of £5,000 for the work of an entrant aged between 18 and 30. Both Peiyuan Jiang and Robert O'Brien are eligible for this award of £5,000.

Untitled by Peiyuan Jiang. © Peiyuan Jiang

Simon Davis (born 1968) has been selected for his Portrait of Amanda Smith at Vincent Avenue, which was influenced by a study by Toulouse-Lautrec of his mother.

"I had previously painted a number of closer-in portraits of Amanda," he says, "but this time I wanted the composition to have a calm and contemplative feel to it with a lot of space around it."

Peiyuan Jiang (born 1983) made the shortlist for Untitled, an oil portrait of his flatmate. Jiang is influenced by the Pre-Raphaelites and he painted the portrait of his flatmate only one week after meeting her for the first time.

"Ever since I saw the BP Portrait Prize last year," he said. "I'd intended to enter and had been looking for a subject. I only know a little bit about this woman, the small things you glean from being housemates."

Robert O'Brien (born 1978) has made the shortlist for his oil portrait of his grandmother Hannah O'Brien who died on October 26 2007.

The sittings, which were kept short because of her poor health, took place in the Grange Care Centre, Hayes, Middlesex. "I've always thought of my Grandmother as a strong, determined woman," said Robert, "who overcame great hardships and difficulties in her life and that is how I wanted to portray her."

K by Craig Wylie, © Craig Wylie

Craig Wylie (born 1973) has made the final four for K, an oil portrait of his girlfriend Katherine Raw.

The work is based on photographs taken in Wylie's Hackney Wick studio in 2005. He made two previous attempts at this painting through 2006, starting the final version in 2007. "On one level the viewer's intrusion into the sitters emotional state is tacitly accepted," he said, "on another it is positively rebuffed."

The Portrait Award, now in its 29th year at the National Portrait Gallery, is aimed at encouraging artists to focus upon, and develop, the theme of painted portraiture within their work.

The winners will be announced on the evening of Monday June 16.