A police tent covers the the spot in Salisbury, England, Tuesday, March 6, 2018, where former Russian spy double agent Sergei Skripal and his companion were found critically ill Sunday following exposure to an "unknown substance". 66-year old Skripal, and unidentified woman companion are being treated in hospital, after they were found unconscious on the park bench.(AP Photo/Frank Augstein)

A police tent covers the the spot in Salisbury, England, Tuesday, March 6, 2018, where former Russian spy double agent Sergei Skripal and his companion were found critically ill Sunday following exposure to an "unknown substance". 66-year old Skripal, and unidentified woman companion are being treated in hospital, after they were found unconscious on the park bench.(AP Photo/Frank Augstein)

LONDON (AP) — The British government says politicians might not attend the World Cup in Russia if Moscow is proven to be behind the unexplained illness of a former spy.

Sergei Skripal and his daughter are in critical condition after collapsing in the English city of Salisbury on Sunday.

Foreign Secretary Boris Johnson told the House of Commons there would be a “robust” British response if Russian involvement is proven, which could possibly impact on the participation in the World Cup.

Johnson said “it will be very difficult to imagine that U.K. representation at that event will go ahead in the normal way.”

The Foreign Office later clarified that the comment referred to dignitaries and officials, not the England soccer team, which is scheduled to compete at the tournament, which starts in June.