The arrival in Moscow of up to 50,000 Chelsea and Manchester United fans for today's Champions League final represents the greatest cultural exchange between Britain and Russia in modern history. For two countries that seem fated to be fascinated by each other, it also threatens to be a make-or-break day in modern relations. Many Muscovites are in for a shock.

Russians have been reared on classical images of England as a land of good manners and gentlemen spies in the James Bond mould. This is a country devoted to Sherlock Holmes, which thought it an elementary courtesy to erect a statue in honour of the great English detective in Moscow last year.

The image of the cultured Englishman is so pervasive that the influential Izvestia newspaper lauded the arrival of the first fans with a geographically shaky front-page story headlined “The countrymen of Oscar Wilde and Bernard Shaw are coming to Moscow”.

Most of the English fans are likely to disappoint locals eager to debate Shavian philosophy. Instead, Russians keen to practise their schoolbook English may get a crash course in the finer arts of swearing and street slang.

The English football hooligan seems a slightly mythical figure for most Muscovites, out of keeping with Britain's refined image. They have seen him on television but have yet to encounter in real life the bare-chested, beer-bellied English hordes that have terrorised bars and public squares all over Europe. Consequently, they are not boarding up their shops and locking up their daughters. Russian hooligans, however, are eagerly anticipating the arrival of their heroes.

Hooligan “firms” linked to Russian league clubs take their fashion cues from the violent heyday of English terrace thuggery in the 1980s. They imitate the “casual” clothing style of gangs in films such as The Football Factory and speak in awed tones of the havoc wreaked by the English hooligan “elite”. The Russian authorities were sufficiently worried about any reception that Moscow's hooligans had planned for English fans that the Sports Minister called a summit of supporters this week to warn them off.

Somehow, it was inevitable that Moscow would host the first all-English final of the Champions League at a time when political relations with London are at their chilliest since the Cold War. The Kremlin and Whitehall are both hoping “football diplomacy” will lead to a thaw.

So the fans pouring into Luzhniki stadium for tonight's game might not realise it, or care, but they hold the future of Anglo-Russian relations in their hands. If the final passes off calmly, London and Moscow will hail it as a new chapter in the enduring friendship between two proud peoples. But if Moscow witnesses the sort of violence that scarred Manchester at last week's Uefa Cup final, even Sherlock Holmes won't be able to save the shattered Russian image of the civilised English gentleman.