A “masterpiece” painting worth nearly £3 million has been blocked from leaving the UK.

The valuable creation, The Lake Of Albano And Castel Gandolfo, has been dubbed the “greatest British watercolour of the 18th century”.

Culture Secretary Jeremy Wright has moved to prevent the painting being sold outside the UK, and retain the piece to inspire future generations of British painters.

It was painted by John Robert Cozens who spent three years painting in Italy and Switzerland between 1776 and 1779.

The Lake Of Albano And Castel Gandolfo (DCMS)

His painting captures a moody view of a hilltop town near Rome, famed for the Pope’s summer palace.

Mr Wright said: “This stunning masterpiece by Cozens is said to be the greatest British watercolour of the 18th century, and we want this important piece of our nation’s artistic history to remain in the UK.

“I hope that a buyer can be found so The Lake Of Albano And Castel Gandolfo can be put on public display to be admired and inspire the next generation of landscape artists.”

The painting, valued at £2.9 million, has been barred from export after a sale was agreed with an overseas buyer.

It has been named Cozens’ best creation, and important due to the artist’s influence on later generations of British painters.

John Constable called him “the greatest genius that ever touched landscape”.

The Reviewing Committee On The Export Of Works Of Art And Objects Of Cultural Interest (RCEWA) recommended the painting be kept in the UK.

RCEWA member Aidan Weston-Lewis said: “This watercolour has twice broken the auction record for a work by Cozens, and is justifiably heralded as one of the supreme achievements of 18th-century British watercolour painting.”

The decision on the export licence applications for the painting will be deferred until September 20.

This may be extended if a serious attempt to raise funds to purchase it is made at the recommended price of £2.9 million.