Gallery assistants hold artwork titled 'Femme nue couchee au collier', standing next to 'Femme assise dans un fauteuil noir', both by painter Pablo Picasso, during a photocall at Christie's auction house. | HENRY NICHOLLS

Paintings by Pablo Picasso, Rene Magritte and Joan Miro as well as Banksy's tribute to Britain's National Health Service are among a selection of artworks going under the hammer this month at auction house Christie's 20th Century Art sale.

To be held in London on March 23, the auction counts 55 lots, including Picasso's "Femme nue couchée au collier", which has a price estimate of 9 million pounds - 15 million pounds ($12.50 million - $21 million).

Another portrait by the Spanish artist, "Femme assise dans un fauteuil noir", is seen selling for 6 million - 9 million pounds.

Gallery assistants hold artwork titled 'Self Portrait' by Jean-Michel Basquiat during a photocall at Christie's auction house, in London

Other lots include a self-portrait by Jean-Michel Basquiat, Amedeo Modigliani's "Portrait du photographe Dilewski" and Andy Warhol's "Three Self-Portraits".

A gallery assistant poses with artwork titled 'Three Self-Portraits' by Andy Warhol, during a photocall at Christie's auction house, in London

"It's all about 20th century art with some 21st century art thrown in as well ... The works in the sale are predominantly fresh to market which is what our clients want," Keith Gill, co-head of the 20th Century Evening Sale, told Reuters.

When asked about the impact of Brexit on art sales in London, he added: "As far as we can tell our sales are going from strength to strength".

"Game Changer", by elusive British street artist Banksy and depicting a boy playing with a nurse as a superhero rather than Batman and Spiderman, has a price estimate of 2.5 million - 3.5 million pounds.

The painting, unveiled last year at University Hospital Southampton, paid tribute to the frontline workers of Britain's National Health Service (NHS) in their fight against the COVID-19 pandemic. Proceeds from the sale will go to the NHS.

Christie's will also hold its Art of the Surreal auction on the same day.

A gallery assistant poses alongside artwork titled 'Le Mois des Vendanges' by painter Rene Magritte during a photocall at Christie's auction house, in London

Highlights include Rene Magritte's "Le mois des vendanges", which has an estimate of 10 million - 15 million pounds and Joan Miro's "Peinture", with a price tag of 9 million - 14 million pounds among the 27 lots.

Christies 20th Century art evening sale