LONDON (Reuters) - Britain will expel 23 Russian diplomats in retaliation for a chemical attack on a former Russian double agent, Prime Minister Theresa May said on Wednesday.

Police tape and bagged items are seen near an inflatable structure in the courtyard of Ashley Wood Recovery; where emergency services worked following the poisoning of former Russian intelligence officer Sergei Skripal and his daughter Yulia; in Salisbury, Britain March 14, 2018. REUTERS/Henry Nicholls

Sergei 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 ever since.

Below is a list of the actions set out by May in parliament on Wednesday:

- Britain will expel 23 Russian diplomats who it says have been identified as undeclared intelligence officers.

“They have just one week to leave,” May said. “This will be the single biggest expulsion for over thirty years and it reflects the fact that this is not the first time that the Russian State has acted against our country.”

- Britain “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”.

- Britain will develop new laws to harden its defences against all forms of “hostile state activity” including being able to detain those suspected of hostile state activity at Britain’s borders. Currently this power is only used in relation to those suspected of terrorism.

- No British ministers or members of the Royal Family will attend this year’s soccer World Cup. Britain will suspend all planned high level bi-lateral contacts between the UK and the Russian Federation.

- All capabilities of UK law enforcement will be brought to bear against “serious criminals and corrupt elites”, May says, adding that there is there is “no place” for them or their money in Britain.

- Britain will “fundamentally degrade” Russian intelligence capability in the UK for years to come and prevent them from rebuilding it.

- Britain will start to monitor and track the intentions of those travelling to the UK who could be engaged in activity that threatens Britain and its allies. “We will increase checks on private flights, customs and freight,” she said.

- Britain’s interior minister will consider whether new counter-espionage powers are needed to clamp down on hostile activities of foreign agents in Britain.

- Britain will seek to strengthen its power to impose sanctions in response to the violations of human rights. “In doing so, we will play our part in an international effort to punish those responsible for the sorts of abuses suffered by Sergei Magnitsky,” May said.

- May said “it is tragic that President Putin has chosen to act in this way”, adding that she has no disagreement with Russian people or Russian citizens living in Britain in a law-abiding away.