Boris Johnson has claimed England could pull out of the World Cup if there is a proven link between Russia and the recent 'poisoning attempt' of a former spy.
Sergei Skripal is in a critical condition and there are suspicions there has been a deliberate attempt to poison him.
Skripal, 66, and his 33-year-old daughter were exposed to what police said was an unknown substance in the English city of Salisbury. Both are still critically ill in intensive care.
"We don't know exactly what has taken place in Salisbury, but if it's as bad as it looks, it is another crime in the litany of crimes that we can lay at Russia's door," Johnson told the British parliament.
"It is clear that Russia, I'm afraid, is now in many respects a malign and disruptive force, and the UK is in the lead across the world in trying to counteract that activity.
“I think it will be difficult to see how UK representation at the World Cup (in Russia) can go ahead."
If Moscow was shown to be behind Skripal's illness, Johnson said, it would be difficult to see how Britain could attend the World Cup in Russia in June and July.
A previous British inquiry said President Vladimir Putin probably approved the 2006 murder of ex-KGB agent Alexander Litvinenko with radioactive polonium-210 in London. The Kremlin has repeatedly denied any involvement in Litvinenko's killing.
Litvinenko, 43, an outspoken critic of Putin who fled Russia for Britain six years before he was poisoned, died after drinking green tea laced with the rare and very potent radioactive isotope at London's Millennium Hotel.
