Tracey Emin has delivered a petition signed by several prominent artists to 10 Downing Street in support of an effort to keep two masterpieces by Titian in the U.K, the BBC reports.

Signed by such artists as Lucian Freud, Damien Hirst, and David Hockney, the petition calls on the U.K. government to support the effort to purchase the two paintings — which it describes as “among the finest works in private hands in the world.”

The national galleries of Scotland and London are in the midst of a joint effort to raise £50 million ($77.2 million) to purchase the first of the two works, Diana and Actaeon, by December 31.

If they are successful, the second piece — Diana and Callisto — will also be offered to them.

The paintings are being sold by the Duke of Sutherland. The £50 million price per painting is estimated to be a third of what the paintings could fetch on the open market.