England must boycott the World Cup - for their own safety - if Vladimir Putin is behind the attempted murder of a former Russian spy and his daughter in Salisbury, a security and intelligence expert has warned.
Gareth Southgate's side were told they would be "in harm's way" at the tournament if the nerve-agent attack that left Sergei Skripal and his daughter fighting for their lives and put a police officer in intensive care prompts retaliatory action by the UK.
Anthony Glees, head of the University of Buckingham's Centre for Security and Intelligence Studies, said any retaliation must include a World Cup boycott to be credible. And he warned that, if it did not, the England team would be at the mercy of Russian president Putin.
"If Putin was involved and this were to go ahead, the team would be putting themselves in harm's way," Glees claimed.
"However, I don't think it would come to that. Because, if Putin is involved, we would have to call off this thing and that would be the least of the measures we would have to take. It would be the least of things a British government that was worth its name would have to do in order to teach Putin a lesson.
'DON'T DRINK RUSSIAN WATER'
"We cannot let the Russians regard the United Kingdom as a place where they can come and kill people with impunity."
Another intelligence expert, Edward Lucas, claimed this week that Russia could sabotage England at the World Cup by poisoning their players or rigging drugs tests.
Glees said even if the Russian state had nothing to do with Sunday's crime, Southgate's side were "still at risk" of such sabotage at the World Cup. He added: "They should take water from England with them and it should be bottled and sealed. And they should use that water for everything - for showering, for brushing their teeth.
"People can get things into the water supply, very easily, of hotels. If you go into a space that is fundamentally unsafe, even if you encapsulate yourself, you're still at risk."
The Football Association declined to comment, but is understood to be confident in its World Cup security arrangements and that of Fifa, which will provide bottled water to teams. England will also bring their own chefs to the tournament, as well as some food, though they will also have to eat food sourced in Russia.
Players and staff will be advised not to use public or hotel wi-fi while in the country over hacking fears because the FA is concerned sensitive information such as injury, squad selection and tactical details could be exposed...