The British government has put a temporary export ban on J. M. W. Turner’s Modern Rome – Campo Vaccino, the dreamily beautiful masterpiece that was the artist’s last painting of Rome.

It sold at auction in July for $45 million, but even then the Getty knew they weren’t likely to get their hands on it anytime soon because UK law delays export of significant artistic and historical pieces that have been in the country for at least 50 years to give local institutions a chance to raise the sale price. If a British museum can raise the money, the Getty will be forced to accept payment and the Turner will remain in the country.

Culture Minister Ed Vaizey announced the decision on Wednesday, and gave individuals and organizations until February 2, 2011 to demonstrate serious intent to keep the masterpiece in the country by meeting its market value.

If it appears to be a real possibility that the funds can be raised, the deadline will be extended to August 2 next year, he said in a statement.

When the painting sold this summer, the buzz was that the in-country museums like the Tate Gallery and British Museum weren’t likely to seek out such a huge sum for a Turner since they already have a notable collection and that kind of money is hard to come by these days. The Getty Trust, on the other hand, was very excited to have snagged this piece because it would make Los Angeles the city in the US with the third most Turners after New Haven and Washington, D.C.

The ruling follows the recommendation of the Reviewing Committee on the Export of Works of Art and Objects of Cultural Interest, administered by the Museums, Libraries and Archives Council (MLA), which assesses each object individually to determine whether it’s in the country’s cultural interest to allow a piece to be sold abroad. Lord Inglewood, chairman of the Reviewing Committee, pointed out that even though the UK has the great number of Turner’s paintings, Campo Vaccino is a particularly stellar example of his oeuvre. It’s in outstanding condition (it has only had 2 owners since it was painted in 1839 and both of them treated it with kid gloves) and, as the good Lord puts it, “in a single painting it sums up Northern Europe’s centuries old attitude towards the Mediterranean and the Classical World and its seduction by them.”

The Getty has no choice but to wait it out, and they’re being very pleasant about it. They have tasted the bitter gall of an export ban before. In 2004, the British Museum bought Raphael’s Madonna of the Pinks out from under them thanks to an export ban and feverish fund raising. There was a lot more cash in budgets back then, though. The Getty has reason for optimism.