LONDON, England (CNN) -- English football fans hoping to travel to Moscow for this month's Champions League final between Manchester United and Chelsea face spiraling costs and an anxious wait for visas amid a simmering diplomatic row between the UK and Russia.
Chelsea fans hoping to follow their side to Moscow face hefty expenses and an anxious wait over visas.
Upwards of 50,000 fans are expected to travel to the May 21 match from the UK, defying expensive flights and warnings about a shortage of accommodation in the Russian capital -- one of the world's most expensive cities.
But there were fears on Thursday that Russia's stringent visa requirements for British citizens could further complicate matters for fans.
In a statement, the Russian Embassy in London pledged to fulfil its obligations to enable all fans with tickets to the game to travel.
But it also criticized the UK government for tightening restrictions on Russians traveling in the opposite direction, imposed following the apparent murder of the exiled Russian dissident Alexander Litvinenko in 2006.
"If we had an agreement similar to the one Russia has in place with EU, most problems could have been avoided," the statement said.
The embassy also criticized the UK for imposing "cumbersome" visa requirements on supporters of the Russian side, Zenit St. Petersburg, which could reach the UEFA Cup final in Manchester on May 14, including biometric tests, online-only applications and interviews with consulate officials.
But there was speculation as well on Thursday that Moscow may be prepared to temporarily lift some visa requirements in a gesture of good will.
The UK's Times newspaper quoted a foreign ministry spokesman as saying that Russian authorities would waive the need for visa applicants to produce a letter of invitation in the case of ticket holders.
UEFA communications director William Gaillard praised Russia's flexibility on Wednesday and said a simplified visa application procedure could be in place by the end of the week.
"The Russians have shown great flexibility and hopefully within the next 48 hours we will be announcing a more simplified procedure for visas to make it easier for fans to get to Moscow," Gaillard told the UK's Press Association.
Manchester United Chief Executive David Gill said on Wednesday that those traveling on official club packages were assured of a visa.
"If you are on an organized trip, your ticket will be your visa. The actual specifics and fine details will be addressed in the next day or so and then we will communicate with the fans.
"Everyone recognizes in order for it to be a showcase, which it clearly will be, you have to ease entry into the country while not totally doing away with what the Russian authorities require."
But Gill warned that demand for tickets would leave many fans disappointed: "We could sell well over 100,000 tickets for this final, so there will be a lot of disappointed people."
Both United and Chelsea have each received around 21,000 tickets for the match. But with officially allocated tickets expected to be snapped up by season ticket holders and loyalty scheme members, many more fans are expected to travel to Moscow independently.
Flights from London to Moscow on the day of the match, returning the following day were available for around $1,600 over the internet on Thursday.
But the British foreign office Web site advised Thursday that there were no hotel vacancies in Moscow and warned supporters that they would not be able to find a room on arrival.
Meanwhile, UK sports minister Gerry Sutcliffe urged fans to be on their best behavior in Moscow, warning that trouble could derail England's bid to host the 2018 World Cup.
"I was really impressed and pleased that the European champions final will be an all-English final but that brings some responsibilities for the teams involved and their supporters," Sutcliffe told PA.
"It should be a great advert for the Premier League and for English football but it will also be the place everyone will be looking at if anything goes wrong.
"If that happened it would not only be damaging for the two teams participating but could also have a big impact on the reputation of our game at a time when we are trying to encourage football nations to support our World Cup bid."
With the match due to kick off at 2245 local time, the British foreign office Web site advised supporters "not to let alcohol spoil their Champions League final experience," pointing out that smoking and drinking in Red Square are illegal.
"The Foreign and Commonwealth Office is providing detailed information for those fans who are traveling," said minister for Europe Jim Murphy.
"So I encourage those who are going, to look at the specific travel advice on how to enjoy a trouble-free and successful visit to Moscow." E-mail to a friend