Renowned auction houses Sotheby's and Christie's go head-to-head in London next week, holding art sales which are expected to fetch a total of over �400m.

Monet's Nympheas, from his famous water lilies series, has not been seen in public since 1936. It is expected to fetch between �10-15m at Sotheby's on 19 June.

Christie's also has a Monet up for grabs at its Impressionist and Modern Art sale on 18 June. Les Arceaux de Roses, Giverny, could bring in between �9-12m.

Both auction houses also have Francis Bacon works up for sale. On offer at Sotheby's on 21 June, this is Bacon's only full-length self-portrait ever to be offered at auction.

Bacon's Landscape with a Car is one of the highlights of Christie's post-war and contemporary art sale on 20 June. It could fetch between �4m and �6m.

Bacon's Two Men Working in a Field is described by Christie's as one of the artist's most enigmatic works. It could fetch up to �7m.

Lucian Freud's portrait of Bruce Bernard is expected to break the artist's record - currently �4.1m - when it goes on sale at Christie's next week.

Andy Warhol's Three Marilyns - from 1962 - could fetch up to �7m at Christie's. Another Warhol work based on the iconic film star recently sold for $28m (�14m) in New York.

A member of Damien Hirst's team puts the finishing touches to his work, Lullaby Spring, which contains over 6,000 hand-cast pills. It goes up for auction at Sotheby's on 21 June.