London

BRITAIN will expel 23 Russian diplomats in retaliation for the nerve agent attack on a former Russian double agent, Prime Minister Theresa May said on Wednesday.

"Under the Vienna Convention, the United Kingdom will now expel 23 Russian diplomats who have been identified as undeclared intelligence officers," Mrs May told Parliament. "They have just one week to leave."

Mrs May said that the biggest expulsions from London in 30 years would degrade Russian intelligence capabilities in Britain for years to come.

"We will freeze Russian state assets wherever we have the evidence that they may be used to threaten the life or property of UK nationals or residents," she said.

The British leader said that she had come to the conclusion that Russia was culpable for the attempted murder of Sergei Skripal and his daughter. Mr Skripal, 66, and his daughter Yulia, 33, were found slumped unconscious on a bench outside a shopping centre in the genteel southern English city of Salisbury on March 4. They have been in a critical condition in hospital ever since.

"There is no alternative conclusion, other than that the Russian state was culpable for the attempted murder of Mr Skripal and his daughter, and for threatening the lives of other British citizens in Salisbury," Mrs May said. "This represents an unlawful use of force by the Russian state against the United Kingdom," she said. "It must therefore be met with a full and robust response."

She said that she had agreed with Britain's National Security Council to suspend all high-level contacts between her country and Russia, and to expel 23 Russian diplomats, who have one week to leave. She described it as the biggest expulsion in more than 30 years.

Further action could be taken in secret, she warned, a possible hint that Britain could launch cyber attacks. The reprisals come after Russia refused to recognise a deadline of midnight on Tuesday to provide an explanation for the nerve agent attack. "Their response has demonstrated complete disdain for the gravity of these events - they have provided no explanation," Mrs May told Members of Parliament in London.

Mrs May blamed Russian President Vladimir Putin for a deterioration of relations between Moscow and London. "Many of us looked at a post-Soviet Russia with hope. We wanted a better relationship, and it is tragic that President Putin has chosen to act in this way."

The prime minister also announced that British royals and government ministers will not be attending the World Cup in Russia. "There will be no attendance by ministers - or indeed members of the royal family - at this summer's World Cup in Russia," she told lawmakers.

Russia said that Britain should expect retaliation for its actions. Russian Foreign Minister Sergey Lavrov said on Wednesday that Britain was "acting out political drama" rather than investigating the matter seriously.

"Russia could not have had any motives" for the attack, he said, "but those who would like to continue a Russophobic campaign in absolutely all areas of human activities" could have had such motives.

Moscow has demanded that it be part of a joint investigation into the attack on the Skripals, along with the Organization for the Prohibition of Chemical Weapons, and that Britain turn over a sample of the nerve agent.

Mrs May identified the chemical as a Novichok, a class of extremely deadly nerve agents developed by the Soviet Union in the 1970s and 1980s.

The crisis is a key test for Mrs May as she navigates "Brexit" and for the wider Western alliance in how it responds to Mr Putin on the eve of Russian elections. On Tuesday, US President Donald Trump said that he backed her "all the way". REUTERS, BLOOMBERG, AFP