United Kingdom Foreign Secretary Boris Johnson said Britain may not participate "in the normal way" in this summer's World Cup in Russia if Moscow is proven to be behind the unexplained illness of a former spy.
Sergei Skripal, 66, and his 33-year-old daughter Yulia are in a critical condition after collapsing in the English city of Salisbury on Sunday.
Johnson told members of Parliament in the House of Commons that Britain will have a "robust" response if Russian involvement is proven, including sanctions and other measures.
England was the only team from the UK to qualify for tournament, which is scheduled to take place in June and July.
Johnson said that if Russian involvement is proved, "it will be very difficult to imagine that UK representation at that event will go ahead in the normal way."
He added that Russia 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."
The Conservative MP for Henley said that while he was not now "pointing fingers at anyone, I say to governments around the world that no attempt to take innocent life on UK soil will go either unsanctioned or unpunished."
Skripal was convicted in 2006 of passing state secrets to MI6 before being given refuge in the UK as part of a spy swap.
The former colonel in Russian military intelligence, who was sentenced to 13 years in prison, was among four convicts who were given pardons and one of two sent to Britain in 2010 in a deal that was said at the time to be the largest exchange since the Cold War.
He was found along with his daughter on a bench in The Maltings in Salisbury after police were called by a concerned member of the public at around 4.15 p.m. on Sunday.
The pair did not have any visible injuries and were taken to Salisbury District Hospital, where they are being treated in intensive care for "suspected exposure to an unknown substance."
Information from the Press Association was used in this report.