The Government has put a temporary export bar on an unfinished portrait by French impressionist Edouard Manet.
The work, called Portrait of Mademoiselle Claus, dates from 1868. It was bought by American painter John Singer Sargent in 1884 after Manet's death, and has remained in the United Kingdom ever since.
Today's decision, which provides a last chance to raise the money needed to keep the picture in the country, comes after a recommendation by the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest.
Committee member Lowell Libson said: "Manet, one of the most important painters of the 19th century, had a profound influence on the development of Impressionism and this painting demonstrates his ability to innovate while working with a framework of historical reference and allusion.
"The painting in its unfinished state adds to its interest, revealing the artist's creative process, whilst emphasising the haunting beauty of the portrait."
The export bar will run out in February but can be extended to August if "a serious intention" to raise the recommended price of £28,350,000 is expressed.