The Venice vs Portsmouth debate

This picture was painted by one of the most influential artists Britain has ever produced, and is one of two masterpieces that art historians have long asserted were painted in Venice.

Now the Evening Standard can reveal compelling new evidence, uncovered at Tate Britain, that the two JMW Turner paintings are not of the Italian city but of that other great coastal metropolis: Portsmouth.

A Tate spokesman said: "Venice and Portsmouth are, of course, rather different places but we are confident this new research has identified the most likely setting for these wonderfully atmospheric Turners."

So convincing is curator Ian Warrell's argument that the gallery has now given the paintings - which both exhibit Turner's famed mastery of light and colour - entirely new names.

The painting known as Procession Of Boats With Distant Smoke, Venice, will now be called The Disembarkation Of Louis-Philippe At Portsmouth.

And the painting entitled Festive Lagoon Scene, Venice, will now be catalogued as The Arrival Of Louis-Philippe At Portsmouth.

The paintings are typical of Turner, whose work is seen as a major influence on the great Impressionists.

Mr Warrell's discovery is revealed in his catalogue essay for the new Tate Britain exhibition Turner And Venice, which opens to the public next month.

His first piece of evidence is that the two paintings are "substantially" larger than the others in Turner's series of Venetian scenes.

"This is an important point," writes Mr Warrell, "for he imposed fairly rigid limitations on himself with regard to his materials when working in series."