Green MP Caroline Lucas has vowed not to be “silenced” after Tory MPs tried to shout down her question about the Cambridge Analytica scandal. 

Speaker John Bercow was forced to reprimand Conservatives during a hostile PMQs in the Commons on Wednesday as they jeered at Lucas and two SNP MPs who challenged Theresa May on the issue.  

Lucas called for the PM to back “urgent cross-party talks” on revelations about the use of big data.

But before she could conclude her question, Conservative MPs erupted with anger and Bercow was forced to intervene to keep them quiet. 

SNP MPs Ian Blackford and Alan Brown also faced shouts and jeers from the Government benches when they asked about Scottish Tory links to AggregateIQ – a Cambridge Analytica-associated firm.

It comes as questions continue to swirl about spending during the EU referendum and the Brexit campaign links to Cambridge Analytica, which is accused of mining Facebook data, some of which may have been harvested without consent. 

Lucas said the scandal must lead to a tightening-up of electoral law.

“The Cambridge Analytica revelations suggest that there is something rotten in the state of our democracy,” she said.  

“The current electoral law is woefully inadequate in dealing with the combination of big money and big data.

“Will the Prime Minister commit to urgent cross-party talks to kickstart a process to ensure that we have a regulatory and legal framework that is up to the challenge of dealing with the digital age?” 

After the session, Lucas tweeted: “Tory MPs tried to shout down my question to the Prime Minister today, but I won’t be silenced”. 

Blackford, the SNP’s Westminster leader, meanwhile, used PMQs to tell May “the public must have trust in our political process”, before calling on her to back an investigation into campaign spending during the EU Referendum. 

It comes after the DUP was handed £425,000 by Conservative Research Council, chaired by Richard Cook, the former chair of the Scottish Tories, during the Brexit campaign.

Some of the cash reached AggregateIQ, and Cambridge Analytica whistleblower Chris Wylie told MPs this week he was convinced Vote Leave, BeLeave, Veterans For Britain and the DUP had been working together. 

“The shady business of data mining and undermining electoral law goes right to the heart of the PM’s party,” said Blackford, as DUP MPs, who entered a supply and confidence deal with the Tories last year, shook their heads and Tory MPs bellowed. 

“Will the PM release the full details of the transactions between the DUP and the Scottish Tory-linked CRC?” 

Brown, the SNP MP for Kilmarnock and Loudoun, directed his ire at Brexiteer cabinet ministers Boris Johnson and Michael Gove, who were leading figures in the Vote Leave campaign. 

“Their campaign director Dominic Cummings is quoted in the AggregateIQ as saying: ‘The Vote Leave campaign owes a great deal of its success to the work of AggregateIQ, we couldn’t have done it without them’. 

“How does the PM feel about her ministers being caught red-handed using immoral data mining techniques.” 

May replied to Brown: “He is making certain claims in that question which I do not recognise.” 

She suggested opponents were using the Cambridge Analytica revelations to thwart Brexit. 

The PM had earlier replied to Lucas: “Clearly the allegations relating to Cambridge Analytica are concerning because people should be able to have confidence about how their personal data is being used. 

“I think it is right that we are seeing the Information Commissioner investigating this issue. 

“I expect Facebook, Cambridge Analytica and any other involved to cooperate fully with the Information Commissioner’s office in that investigation which is taking place.”