That's the end of our live coverage for today.

Here's a recap of what has happened:

• The government has said it does not think it necessary to refer the leak to the police and the prime minister's de facto deputy said Theresa May considered the matter closed.
• In the Commons, MPs have called for a criminal inquiry and an investigation into whether the Official Secrets Act has been breached.
• Met Police Commissioner Cressida Dick has said Scotland Yard would need a referral from the Cabinet Office to investigate.
• It follows the sacking of defence secretary Gavin Williamson, who has strenuously denied being responsible for the leak.

Nicola Sturgeon has condemned the "reprehensible" security leak from the National Security Council as she accused Gavin Williamson of behaving for his "own selfish political ends".

The Scottish first minister said the leak from the National Security Council was a "sign of the complete dysfunction at the heart of the UK government".

Asked, during today's First Minister's Questions, whether anyone who breaks the Official Secrets Act should be prosecuted, she said it should be a matter for the police.

She added: "I think any minister that has been found guilty in such a way I think that they lose their job.

"All politicians in government should recognise the responsibility and the privileges we carry and should not be behaving in the way it appears Gavin Williamson was behaving - for their own selfish political ends."

Image source, Getty Images

The World at One
BBC Radio 4

Lord MacDonald QC also says Gavin Williamson could invite police to investigate his case himself, although he says this is unlikely.

He tells the BBC's World at One that in normal circumstances anyone can make a complaint about a crime and police can determine what to investigate.

However, he says while Mr Williamson has used "some very colourful language", it's unlikely he will call for a criminal investigation to clear his name.

"It's fairly unusual for people to turn themselves in to the police and invite the police to investigate them and I wouldn't predict at this stage that's something he's likely to do."

The World at One
BBC Radio 4

A former head of the Crown Prosecution Service, Lord MacDonald QC, says the leak could amount to a breach the Official Secrets Act and warrant a police investigation.

He tells BBC Radio 4's World at One that any unauthorised disclosure from the National Security Council which damages the work of security services would be in breach of the Act.

“If the leak takes place in circumstances which undermine the work of the council and damages the faith of participants in the council that they can be frank and speak in confidence, I would have thought there’s a very strong argument that that damages that work of the security services," he says.

Vicki Young
Chief Political Correspondent

Mr Williamson denies he passed on any information in that 11 minute phone call with the journalist involved.

He feels that he has been the victim of a "stitch-up".

But there's not an awful lot of sympathy from some of his colleagues. One said he was "over-promoted" and "self-serving".

A cabinet member I spoke to earlier simply doesn't believe the denials, saying: "He spoke to the journalist and let's face it, they weren't speaking about the weather."

Danny Shaw
BBC Home Affairs Correspondent

The police would need a Cabinet Office referral to investigate the alleged leak from the National Security Council, the Metropolitan Police Commissioner Cressida Dick has said.

If a referral were to be made she said the Met would assess it before deciding whether to investigate, as part of a formal process in such cases.

A protocol called the 'gateway' process was put in place following a review of the Met inquiry into leaks from the Home Office in 2009 when Damian Green, then an opposition MP, was arrested.

Although police will consider complaints and letters from MPs and anyone else calling for an investigation, Ms Dick said in practice they needed evidence before launching an Official Secrets Act inquiry.

The bar for bringing prosecutions under the Official Secrets Act is very high and cases are rare.

BBC Radio 5 Live

BBC News Channel

A former special adviser to Gavin Williamson has called for the government to release any evidence it has linking the former defence secretary to the leak.

Rob Golledge described the situation surrounding Mr Williamson's sacking as "murky" and said he had "full trust" in him.

Mr Golledge said: "I think we need to have some sort of form of information from the PM to explain what this compelling evidence is. Otherwise, we have this ambiguity where the ex defence secretary is ardent that he hasn't been responsible [for the leak] and the PM says he is.

"So we need some sort of explanation from the PM on this. Similarly I think a police inquiry will benefit the situation."

Following the leak, some MPs have questioned whether the Official Secrets Act has been breached and now want a police investigation.

So how does the law work and what are the penalties?

BBC Reality check explains here.

Change UK MP Anna Soubry says if Gavin Williamson is responsible for the leak, it was motivated by "personal ambition".

“If Gavin Williamson has done this thing, he’s not done it as a point of high principle because he disagrees with a policy," the former Conservative MP tells the BBC.

"Like too many of his colleagues, all that motivates him... is his own personal ambition.”

However, she adds that the matter should be referred to the police to establish whether he was responsible.

“He says he didn’t do it and he’s entitled to clear his name because it is such a serious allegation," she says.

Isle of Wight MP Bob Seely (Con) asks the cabinet minister whether he would accept Huawei is "effectively an arm of the Chinese state".

Mr Lidington said the company was officially owned by its employees and is a privately-owned company.

But, he added, there is "an issue" in that Chinese law "requires all Chinese companies to co-operate with the Chinese state."

"The review of 5G goes beyond a single company or single country," he said.

"What we need to do is to make sure, amongst other objectives, is that we have a diverse marketplace, so that the government has a genuine choice of suppliers available to it."

Conservative MP Tom Pursglove has asked what consequences there would be if evidence came to light which disproved the allegations.

Cabinet Office Minister David Lidington responded by saying he thought the MP was asking him to indulge in "a bit of hypothetical speculation" but added that the PM would wish to be made aware of any such "clear evidence".

"I think the PM would want that reported to immediately and given to her in full," he said.

"That would clearly need to be the provision of information that provided some other credible explanation for the leak that has taken place."

Image source, HoC

Labour MP Chris Bryant says Gavin Williamson should be allowed to prove his innocence in a criminal investigation.

“It’s difficult not to sympathise with the former defence secretary because in a kangaroo court you can’t prove yourself innocent," he tells the Commons.

“If he has done what is alleged then of course he should face the full criminal law.”

Former Attorney General Dominic Grieve says a breakdown in collective cabinet responsibility was partly to blame for the leak.

"Unfortunately what appears to have happened is it has a corrosive quality which starts in the willingness to contradict colleagues over policy issues within the Cabinet and then creeps incrementally into a willingness to brief externally on discussions on an increasingly secret nature," he tells the Commons.

In response, Mr Lidington agreed there was a "corrosive effect of unauthorised disclosures".

He says in both National Security Council discussions and Cabinet, "members should speak with complete candour within the room and shut up when they get outside".

Asked whether the Official Secrets Act has been broken, Mr Lidington says this is a matter for the courts.

He tells the Commons: “That is not a judgement which I or any other minister in any government can make.

"Whether a criminal offence has been committed is a matter for independent prosecution authorities and ultimately for the courts.”

Cabinet Office Minister David Lidington says the purpose of the inquiry was to "maintain the integrity and secrecy essential for the proper conduct" of government.

He tells the Commons: "The problem about this particular case was not so much the question of the material that was disclosed, but the forum from which the leak came."

The leak came from the National Security Council, where secret intelligence can be shared by GCHQ, MI6 and MI5 with ministers.

Image source, Hoc

Labour deputy leader Tom Watson says there should be a police investigation into the leaking of information from the national security council.

He tells the Commons: “The essential point here is that the prime minister has sacked the Secretary of State for defence because she believes there is compelling evidence that he has committed a crime but despite that she does not believe he should face a criminal investigation.

“In what world is it acceptable that the prime minister should be the arbiter of whether a politician she believes is guilty of criminal conduct in office should face a criminal investigation?" he asks.