This week’s Modern and Contemporary Art sales in London were already being viewed with some trepidation before Russia invaded Ukraine. They are always a barometer of the health of the major auction houses, and some have been predicting a further narrowing of the gap between Paris and London. Now, though, auctioneers are braced for a week without Russian buyers and with luxury economies worldwide destabilised by the war.

One director of Sotheby’s, who did not want to be named, said they were checking bulletins hourly to see whether any of their buyers and sellers was on the Government’s sanctions list. A former Sotheby’s lead auctioneer told me: “I would not like to be the auctioneer this week.”

Some concerns have also been raised about third-biggest auction house, Phillips, which is owned by Mercury, a Russian luxury goods company.

Yesterday, to put their clients at ease, Phillips let it be known unofficially that their owners were not the subject of sanctions and have no political or business connection to government or to any individuals or institutions targeted by sanctions. That list of sanctions, of course, is changing quickly. And, inconveniently, a number of the most high-profile lots are by artists popular among Russians.

Top of the menu is a powerful 1980s triptych by Francis Bacon, a favourite in Russia, that is estimated to sell for between £35 million and £55 million. The painting, which is guaranteed, is being sold by the celebrated architect Norman Foster.

There are also works by Impressionists, much favoured by Russian collectors wherever they live. Five Monets come from the collection of Daniel Snyder, the owner of the beleaguered American football club Washington Commanders (formerly the Washington Redskins). The German Expressionists, another area of Russian interest, are led by a 1913 painting of foxes by Franz Marc, sold under duress under the Nazis but now restituted to the owner’s family.

Not everyone is downbeat, however. Sotheby’s, Christie’s and Phillips are still expected to generate some £600 million over the week, 35 per cent up on this time last year, with that Franz Marc touted at a record-busting £35 million. There is also much excitement surrounding a tender naked bust portrait by Lucian Freud of his former lover, the painter Janey Longman, at £10 million to £15 million. The painting comes from the family of established British collectors Ian Stoutzker and his wife, Mercedes.

The highest price of the week is likely to be registered by the surrealist kingpin René Magritte. Sotheby’s is so enamoured of his L’Empire des lumières, which magically juxtaposes a dark-lit street at night against a luminous day-lit sky, it has painted its front exterior to resemble the picture.

Coming from the collection of one of Magritte’s patrons, the painting is said to have been on offer privately at Sotheby’s last year for €100  million (£84 million). But having been unable to place it at that price, they have offered the owner a guarantee in the region of £45 million, whether someone else bids or not. This could be a costly gamble if it backfires.

Guy Jennings, a former auctioneer who is now a director of the Fine Art Group, was previewing the sale yesterday and told The Telegraph that “the mood was upbeat – almost business as usual. The Russians may not buy this week, but they have not been a dominating force outside of the Russian art sales for nearly 10 years, when Russian money was mopping up Impressionist paintings and the likes of Roman Abramovich were paying millions for works by Bacon and Freud. And the Asians are here.”

Melanie Clore, a former chairman of Sotheby’s Europe and co-founder of the art advisory Clore Wyndham, reminds us how resilient the market is. “The 2008 financial recession did not immediately affect the art market, nor did the pandemic,” she said.

“Of course, the current political situation is utterly deplorable, but great art is still great art, and real collectors, as opposed to speculators, will still want to buy. Also, while the Russians won’t be buying, the market is so global it is not overly affected when a single nation withdraws.”

Specialist Russian art dealer, James Butterwick, is looking on the bright side. “I am the biggest Ukrainian art dealer in the West – and that could just be an advantage.”

But as far as the larger market is concerned, he says: “No one can predict the real impact of this war. We’ll have a better idea by the end of this week.”