The above quote came from Conservative backbencher Sir Edward Leigh, a 68-year-old party stalwart and former minister. He, like many, has little doubt as to who was behind the assassination attempt. "The circumstantial evidence against Russia is strong,” he said. “Who else would have the motive and the means? "Those of us who seek to understand Russia know that the only way to preserve peace is through strength.” Loading Replay Replay video Play video Play video

Leigh is no Russiaphobe. In 2014 he said Britain should “accommodate” Vladimir Putin’s invasion of Ukraine because the country was “part of the Russian soul”. And in December he attacked Labour for “seeing reds under every bed”, dismissing claims that Russia was interfering in Western democracies as paranoia and the country was being used as an “excuse” for the failure of the liberal left. So the fact that Leigh is now baying for Russian blood is a sign of the fury building in Westminster and Whitehall. Defence Secretary Gavin Williamson told the BBC the government was being “pushed around” by Russia and “we have to change the way we deal with it” – though he stopped short of blaming it for the Salisbury attack. Tom Tugendhat, chairman of the Foreign Affairs Select Committee, said: “The first duty of government is to protect the British people - I think using nerve agents on British streets really does demand a response.”

Tory MP Nigel Huddleston worried about the cruel nature of the crime "which could have resulted in considerably greater collateral damage" and demanded perpetrators be brought down by the "full force of the law". A police officer without protective gear crouches down next to the bench at the shopping centre where Sergei Skripal and his daughter Yulia were found on Sunday. Credit:AP But Whitehall officials are still very, very keen not to speculate on whether Russia was behind the attack, still less on what might happen if they were. They talk about a process: first comes the evidence, then a response will be considered. They politely but firmly decline to reveal what level of evidence is required before retaliating. At government level, anger is still mostly caged behind rhetoric.

Prime Minister Theresa May said the police “needed space and time to conduct their investigation”. Prime Minister Theresa May, centre, avoided blaming Russia, for now. Credit:Pool Action would be taken “properly at the right time”, she said, if the attack turned out to have been state-sponsored. She carefully avoided saying “Russia”. Home Secretary Amber Rudd walked a similar tightrope in the House of Commons: she couldn’t downplay the seriousness of the attack, but couldn’t go after Russia without proof of their involvement. “The use of a nerve agent on UK soil is a brazen and reckless act,” she said. “This was attempted murder in the most cruel and public way. People are right to want to know who to hold to account. But, if we are to be rigorous in this investigation, we must avoid speculation and allow the police to carry on their investigation.”

As to what might follow: “It does not help [police] work, which must be our priority, to speculate about what might happen when we make an attribution.” But still she came under pressure, and clearly she did not want to come across as a Kremlin apologist. “Just because we want to approach this with a cool head in order to collect the evidence, it does not mean we do not share the outrage that [Huddleston] and his constituents clearly feel,” Rudd said. “When we have the evidence, I will return to the House.” If/when that moment comes, it’s far from clear what Rudd (or May) could do. Loading

The UK is already part of, and a strong supporter of EU-wide sanctions against Russia, imposed after its annexation of Crimea and action in eastern Ukraine. The sanctions include travel bans and asset freezes on 149 individuals, export bans, and restrictions on access to EU capital markets for Russian banks and oil companies, Any extra sanctions must be agreed by the entire EU. Right now, thanks to tensions between eastern, southern and western Europe, and the rise of pro-Putin politicians in countries such as Hungary and Italy, extra sanctions could be a tough sell. There is also the option of expelling Russian diplomats: the classic bloody nose. The UK thought it had sent a strong message with such action after the murder of Russian expat Alexander Litvenenko in 2006. If Russia is behind the recent attack (and other suspicious deaths which some have attributed to Russian action), that was clearly no deterrent. Another option might be action against the many Russian ex-pats in London. But this is complicated: some are linked to the Kremlin, others are no friends of Putin and more are just apolitical businessmen. They bring lots of money to the capital.

Then there’s the option aired by Foreign Secretary Boris Johnson: the withdrawal of officials (and perhaps Prince William) from the delegation to this summer’s FIFA World Cup to be held in Russia. It’s unlikely the Kremlin is so enamoured of the prince that this will have much impact. Some hope the saga will blow over. There is an unspoken understanding that this is the sort of thing that happens, sometimes, to those who have worked in the world of espionage. Loading “He would have a lot of enemies,” a Russian contact told me.