Russia’s ambassador to London has condemned as “totally irresponsible” Boris Johnson’s comparison of Russia hosting the World Cup to Hitler’s 1936 Olympics .

Speaking at a press conference at the embassy, Alexander Yakovenko said: “I am authorised to say that Moscow considers this kind of statement made under the level of foreign secretary … unacceptable and totally irresponsible.

“The British Government is free to take a decision about its participation in the World Cup.

“But nobody has the right to insult the Russian people, who defeated Nazism and lost more than 25 million people, by comparing our country to Nazi Germany.

“That goes beyond common sense and we do not think British war veterans, including those of the Arctic convoys, would share this opinion.”

Mr Johnson made his comments while giving evidence to the Commons Foreign Affairs Committee on Wednesday.

He said: “I think the comparison to 1936 is certainly right.”

Downing Street said on Thursday Theresa May had “full confidence” in Mr Johnson despite the furore his remarks created.

Culture Secretary Matt Hancock suggested that the best response to Russia hosting the tournament would be for England to win it.

Asked if Mrs May agreed, the Downing Street spokesman said: “I think the Prime Minister would, of course, want our team to win the World Cup.”

Mr Johnson’s comments were branded “utterly disgusting” and “unworthy” of a foreign minister by Russian president Vladimir Putin’s spokesman.

There will be no official UK Government representation at the event as a result of the Novichok nerve agent attack in Salisbury.

Mr Yakovenko urged diplomats to be “very cautious” with their language in order to adhere to “political manners”.

He added: “It’s very difficult for us because we are facing the new reality of the new diplomacy here in the UK.”

He detailed a note he sent to Mr Johnson on Thursday, asking a series of questions about the Salisbury investigation, including the exact diagnosis of the three patients in hospital and what treatment they were being given.

He appeared to suggest the source of the poisoning could have come from Britain, asking whether it had been “coincidence” that Porton Down was not far from the site of the attack.

He told reporters: “Could it mean that it is highly likely that the British authorities already had this nerve agent in their chemical laboratory in Porton Down, which is the largest secret military facility in the UK that has been dealing with chemical weapons?”

The ambassador claimed the embassy had learned about the death of Russian citizen Nikolay Glushkov, which prompted the Metropolitan Police to launch a murder investigation, from the media, and claimed its requests for information from the UK had been ignored.

Mr Yakovenko also defended a seemingly jovial tweet sent from the embassy claiming Agatha Christie sleuth Hercule Poirot was needed to solve the Salisbury case.

He said the case was so complicated that it would require “some wisdom from the person like Poirot to investigate the matter”.

On the tone of the statement, he noted that it had been made on Twitter, adding : “It’s not just a political statement, it’s also for the public. And they like it.”