The Government has put a temporary export bar on an early work by Pablo Picasso in a bid to keep it in the country.
The decision, which provides a last chance to raise the money needed to buy the oil painting, comes after a recommendation by the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest.
The painting, Child with a Dove, dates from 1901 and marks the beginning of Picasso's move into his celebrated Blue Period.
The work, which depicts an image of a young child holding a dove next to a multi-coloured ball, was on loan to the National Gallery for many years until 2010.
Committee member Aidan Weston-Lewis said: "Child with a Dove is a much-loved painting whose iconic status; together with its long history in British collections - latterly on loan to public galleries - make it of outstanding importance to our national heritage."
The decision on the export licence application will be deferred until December 16.
That can be extended to June 16 next year if "a serious intention" is confirmed to buy the painting at the recommended price of £50 million.
Offers from public bodies for less than the recommended price could also be considered.
