MI5 had evidence that Arron Banks ‘ordered surveillance’ of information commissioner, MP claims in Commons

Labour MP alleges Elizabeth Denham was warned by counter-terrorism officers and that ‘her office had to be swept’

‘I’ve heard enough crazy conspiracy theories to last me a lifetime’, the former Leave.EU backer responded (PA Archive)

MI5 gathered evidence that Arron Banks ordered “intrusive surveillance” of the information commissioner during the Cambridge Analytica scandal, a Labour MP has alleged.

Liam Byrne used parliamentary privilege to name Nigel Farage’s former Leave.EU ally during a wider debate on how wealthy people use British courts to silence journalists and regulators.

He told the Commons: “I have been told Elizabeth Denham, who was the information commissioner at the height of the Cambridge Analytica scandal, was warned by counterterrorism officers that MI5 had evidence that she was under active intrusive surveillance ordered by Mr Arron Banks, so her office had to be swept.”

But Mr Banks told The Independent: “I’ve heard enough crazy conspiracy theories to last me a lifetime. I’m not really interested in MPs that use parliamentary privilege to land allegations. Say it outside parliament.”

The Independent also asked the Information Commissioner’s office if it is correct that Ms Denham – who no longer leads the organisation – received the warning, but it declined to comment.

Mr Banks, a multimillionaire businessman, was a figurehead for the successful Brexit referendum in 2016, through his Leave.EU group – which was separate from the Vote Leave campaign, fronted by Boris Johnson.

Cambridge Analytica did work for Leave.EU, emails published by a House of Commons committee later revealed, although the company did not receive payment for it.

In 2018, the firm was embroiled in the scandal over the collection of personal data belonging to millions of Facebook users without their consent, who were targeted for political advertising.

During the Commons debate, the former Conservative cabinet minister David Davis called for a US-style ban on rich individuals using the British legal system to curb free speech.

People with “nefarious intentions” and “exceptionally deep pockets” are able to “threaten, intimidate and put the fear of God into British journalists, citizens, officials and media organisations”, he said.

Bob Seely, also a Conservative MP, said: “The abuse of UK courts by organised crime, oligarchs and authoritarian states and their wretched proxies is, I believe, a significant threat when it comes to the corruption of the UK legal system.”

He added: “If we allow the cancer of the selling of intimidation services by high-end legal firms, it will not do us any good in the long run – just as, in the long run, letting mafias launder money would also be bad for us.”

Mr Byrne told ministers: “Others have told us about the ‘hack and leak’ technique, whereby systems are hacked into and information is then leaked to serve as a trigger for defamation proceedings.”

Stephen Kinnock, a fellow Labour MP, also warned that “Russian-backed interests are hacking people’s private data, leaking it and then suing them for libel”. He called the situation “utterly absurd and unacceptable”.

Cases in which the wealthy take on their critics in the courts have been dubbed SLAPPs (strategic litigation against public participation).

James Cartlidge, justice minister, agreed that “SLAPPs represent an abuse of the legal system”, using “threatening tactics to silence free speech”.

But he told MPs: “We must be cautious to respond to SLAPPs in a proportionate way that continues our tradition of balancing individual rights with the public good.”