Notable pieces by Monet and Warhol are among 150 artworks being auctioned by novelist and former politician Jeffrey Archer.
A silkscreen portrait of Marilyn Monroe by Warhol is expected to achieve £100,000, while Monet's 1878 La Seine pres de Vetheuil, temps orageux could make £800,000 at the Christie's sale on June 28.
The sale is expected to attract serious investors as well as the tabloid newspapers, such is the interest that surrounds Baron Archer of Weston-Super-Mare.
"I recently celebrated my 70th birthday, an event which prompts a certain degree of thought and realization," Archer said in the statement.
"As a result, I have begun to restructure my art collection with a view to the future."
The previous day, Archer will himself auction a number of other items from his personal collection for charity, including the stopwatch used to time Roger Bannister's record breaking four minute mile attempt in May 1954.
Proceeds from the stopwatch will go to the Oxford University Athletics Club. Archer is a former athletics blue for Oxford.
It is hoped the two sales will achieve more than £5m, with many charities expected to benefit, including the Cambridge University Hospitals NHS Foundation Trust, which is chaired by Archer's wife Mary.
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