A Turner painting valued at £2 million has been temporarily banned from going abroad to give UK arts institutions a chance to purchase it for the nation.
The painting shows the mountains encircling the village of Fluelen
The export bar will prevent the current owner from selling the piece to a buyer overseas until 11 January next year.
That deadline may be extended until 11 May 2008 if a "serious" bid is made.
The painting - a view of Lake Lucerne in Switzerland, painted around 1815 - has been described as "one of Turner's finest watercolours".
Its full title is Lake of Lucerne, from the Landing Place at Fluelen, looking towards Bauen and Tell's Chapel, Switzerland.
Culture Minister Margaret Hodge's ruling followed a recommendation that the export decision be deferred due to its "outstanding aesthetic importance".
The recommendation was made by the Reviewing Committee on the Exports of Works of Art and Objects of Cultural Interest, an independent body administered by the Museums, Libraries and Archives Council.
The watercolour, said committee chairman Lord Inglewood, was "one of the very finest achievements in this medium".
The painting, one of four watercolours by Turner shown at the Royal Academy in London in 1815, formed the climax in a series of large-scale depictions of the Alps.
Its current owner's identity and that of the prospective buyer have not been disclosed.