Boris Johnson says English officials could refuse to attend this year's World Cup over the alleged poisoning of Sergei Skripal.

It is "difficult to see" how England could participate in the footballing tournament in Russia as normal if the Kremlin is behind the alleged poisoning, the foreign secretary said.

Skripal, a former Russian intelligence official, was rushed to hospital with his daughter after a meal in south England on Sunday.

LONDON — Boris Johnson today suggested the UK could boycott this year's World Cup in Russia if evidence shows the Kremlin is behind the poisoning of Sergei Skripal.

The foreign secretary said on Tuesday afternoon that it would be "difficult to see" how the UK could participate in the tournament as normal if Vladimir Putin's Russia was behind the poisoning of Skripal.

"If things turn out to be as many members suspect that they are... I think we will have to have a serious conversation about our engagement with Russia," the Conservative minister told MPs.

"For my own part, I think it will be very difficult to see how... thinking ahead to the World Cup this July, this summer... I think it would be that it would be difficult to imagine that UK representation at that event could go ahead in the normal way.

"We will certainly have to consider that."

A spokesperson for the foreign secretary told Business Insider that he had only been referring to UK officials, rather than the football team itself.

A spokesperson for Prime Minister Theresa May later added: "The foreign secretary's aides have been clear he was making a reference to diplomatic and political representation to the World Cup."

The World Cup will get underway on June 14 across 11 cities in Russia. England's opening game is set to be against Tunisia on Monday, June 18.

However, Johnson today cast doubt over England's involvement in the event if the investigation into the Skripal case suggests the Russian state was involved in the poisoning of the former spy and his daughter.

Skripal, 66-year-old former Russian intelligence official, and his daughter, Yulia Skripal, 33, were found collapsed on a bench at a shopping centre in Salisbury, south England, on Sunday. Both are in critical condition at a nearby hospital.

Johnson was addressing the House of Commons following an urgent question from Conservative MP, Tom Tugendhat, regarding the poisoning of Skripal and his daughter.

"Russia is in many respects a malign and disruptive force," the foreign secretary told MPs, as he described the alleged poisoning of Skripal as a potential "act of war."

The UK foreign secretary said the Skripal case had "echoes" of the assassination of Alexander Litvinenko in 2006 and promised a "robust" response if a link is found to Moscow in this case.

"I can reassure the House that should evidence emerge that implies state responsibility then her majesty's government will respond appropriately and robustly," Johnson told MPs.