Theresa May is to chair a meeting of the National Security Council (NSC), amid speculation she is close to blaming Russia for the nerve agent attack on former spy Sergei Skripal and his daughter, Yulia.

At the meeting, where ministers will be briefed on the latest information from the Salisbury attack, the Prime Minister is likely to come under intense pressure to take tough action if a clear link to the Kremlin has been established.

Mr Skripal, a retired Russian military intelligence officer, was convicted by the Russian government of passing secrets to MI6 in 2004, but given refuge in the UK in 2010 as part of a "spy swap".

The 66-year-old and his 33-year-old daughter remain critically ill in hospital, eight days after they were found collapsed on a bench in the Wiltshire city.

Detective Sergeant Nick Bailey, a police officer who helped the pair, remains in a serious but stable condition in Salisbury District Hospital, where he is said to be conscious and talking.

Officials say it is still unclear exactly how and when the nerve agent was administered to the pair, and they are yet to confirm exactly what it was.

The NSC meeting, which brings together senior ministers from relevant departments and is attended by intelligence and military chiefs, come a day after hundreds of people who passed through the area where Mr Skripal and his daughter may have been poisoned, were told to wash their clothes and other items as a precaution.

Investigators found traces of the substance at both a Zizzi restaurant and the Mill pub in central Salisbury, both locations visited by the pair on the afternoon of Sunday, March 4.

Traces of the nerve agent were reportedly found on and around the table where the pair ate at Zizzi, but Scotland Yard, which is running the investigation, would neither confirm nor deny the report.

Possible sanctions against Russia which are likely to be discussed during Monday's meeting could include the expulsion of Russian diplomats and spies from the UK, new financial sanctions against individuals linked to the Kremlin, and the withdrawal of official representation from the 2018 World Cup in Russia.

In other developments in the case on Sunday, Wiltshire Police told residents "not to be alarmed" as counter-terror police were helped by Armed forces, including Royal Marines, in the clean-up operation as:

Also on Monday, Jamie Knight, 30, from Salisbury, will appear before magistrates in Swindon accused of breaching one of the cordons on Friday evening.