Westminster today: Theresa May faces senior MPs questions over Cambridge Analytica and Vote Leave row - as it happened

Stepping away from the committee for a moment, here is some breaking news about the Manchester terror attack last year.

Firefighters did not respond to the Manchester attack for two hours because they believed a gunman could be on the loose, an official report has found.

More here:

Prominent Brexiteer Jacob Rees-Mogg is giving a speech this morning, ahead of the one-year countdown of exit day.

Over in the Commons chamber, Speaker John Bercow has delivered a stinging rebuke to Boris Johnson after he referred to shadow foreign secretary Emily Thornberry as 'Lady Nugee'. Thornberry is married to Sir Christopher Nugee, a high court judge.

Bercow branded the Foreign Secretary as "sexist" and ordered him to apologise.

Back at the committee, Christopher Wylie was asked about Cambridge Analytica’s work for Leave.EU - Nigel Farage and Arron Banks' organisation.

He says the firm were very good a using “weasel words” and it was worth asking if Banks used the data.

Theresa May has told the cabinet that 23 other countries have now expelled more than 115 Russian diplomats in the wake of the Salisbury nerve agent attack. 

Her spokesman told a Westminster briefing that the Prime Minister informed her top team that the international move against Russia was "an unprecedented series of expulsions that has demonstrated to the Kremlin that we will not tolerate their attempts to flout international law, undermine our values or threaten our security."

She added: "It is also important to note that our partners are not only taking these measures out of solidarity with the UK, but also because they recognise the threat that these Russian networks pose to the security of their own countries and the pattern of Russian aggression which has affected us all."

Boris Johnson has been branded “sexist” by the Commons Speaker after using the name of Shadow Foreign Secretary Emily Thornberry’s husband to ridicule her.

The Foreign Secretary sneered at Ms Thornberry as “Lady Nugee” – a reference to her marriage to High Court Judge Sir Christopher Nugee.

“We don’t name call in this chamber,” John Bercow told Mr Johnson in a stern telling off. 

Story here:

Irish foreign minister Simon Coveney has announced that one Russian diplomat will be expelled from Ireland.

"The use of chemical weapons, including the use of any toxic chemicals as weapons, by anyone, anywhere, is particularly shocking and abhorrent," he said.

"The attack in Salisbury was not just an attack against the United Kingdom, but an affront to the international rules-based system on which we all depend for our security and well-being.

"In light of the European Council conclusions, and following an assessment conducted by the security services and relevant departments, I have briefed the Government on my intended course of action.

"The Secretary General of the Department of Foreign Affairs and Trade has subsequently met with the Ambassador of the Russian Federation and informed him that the accreditation of a member of his staff with diplomatic status is to be terminated, in line with the provisions of the Vienna Convention on Diplomatic Relations.

"The individual in question is required to leave the jurisdiction."

Earlier, Christopher Wylie claimed that SCL - a strategic comms firms linked to Cambridge Analytica - had been involved in a project in Nigeria in 2015 which had involved hacking the private information of Muhammadu Buhari, who was running for president.

And he claimed AIQ had distributed compromising material - known as kompromat - and videos designed to intimidate Mr Buhari's supporters.

"The company utilised the services of an Israeli private intelligence firm, Black Cube," he said.

"Black Cube on the Nigeria project was engaged to hack the now-president Buhari to get access to his medical records and private emails.

"AIQ worked on that project. AIQ was handed material in Nigeria from Cambridge Analytica to distribute online. That's distribution of kompromat and of incredibly threatening and violent video content which I've passed on to the committee.

"The videos that AIQ distributed in Nigeria with the sole intent of intimidating voters included content where people were being dismembered, where people were having their throats cut and bled to death in a ditch, they were being burned alive.

"There were incredibly anti-Islamic and threatening messages portraying Muslims as violent."

Mr Wylie also alleged that AIQ had worked on a project in Trinidad & Tobago, which he claimed involved attempting to harvest the internet data of the country's entire population.

He said: "You've got AggregateIQ, who received 40% of Vote Leave's spending, also involved in projects which involved hacked material and kompromat and distributing violent videos of people being bled to death to intimidate voters.

"This is the company that played an incredibly pivotal role in politics here. Something that I would strongly recommend to the committee would be that they push the authorities here and give them the support they need to investigate this company."

Asked if Cambridge Analytica was involved in the Scottish independence referendum in 2014, Christopher Wylie says he is "fuzzy" on the details.

He said "meetings took place" but nothing may have come from it. CA boss Alexander Nix certainly "pitched" for work but Wylie said he wasn't clear on which side he spoke to.