Brexit: Vote Leave chief Dominic Cummings ordered to appear before MPs within days over data row

One of the key figures behind the main Brexit campaign has been ordered to appear before a Commons inquiry into the Facebook data row, in a rare show of parliamentary strength.

MPs ordered former Vote Leave chief Dominic Cummings to give evidence to the Digital, Culture, Media and Sport Committee before June 20, in what is thought to be the first motion of its kind in parliament since 1920.

Mr Cummings, who is widely regarded as the brains behind Brexit, has repeatedly refused to appear before the committee to answer questions over the potential misuse of data during the referendum campaign.

He accused the committee of "grandstanding" when it sought to hold him in contempt of parliament, and said he would give evidence once a separate inquiry by the Electoral Commission had concluded.

Conservative MP Damian Collins, who chairs the committee, said: "We have a unique problem in requiring Dominic Cummings to come and give evidence to us and I do not believe, and the members of my committee do not believe, that that is an acceptable state of affairs.

"These are incredibly serious matters. There's a certain irony that someone who is the communications director of Vote Leave, who ran a successful campaign to seek to restore powers to parliament, seems to hold that institution himself in such contempt.

"His decision not to come, whatever he says, is one of his own making, it's a deliberate attempt to deny parliament its right to question witnesses on matters of importance."

Mr Cummings held a "very, very important position in this country during a very, very important campaign" and he should answer questions in parliament, Mr Collins added.

Hilary Benn, Labour chairman of the Brexit Committee, said: "This unfortunate case and the response of Mr Cummings reminds us of the need to ensure we end up with a system that doesn't allow the powerful and people who need to answer questions and be held to account for what they have done in the normal, courteous manner that almost all select committees operate under.

"We cannot allow that to happen because if we do, then we cannot do our job on behalf of the people who send us here."

Commons leader Andrea Leadsom supported the motion, while influential Conservative backbencher Sarah Wollaston labelled Mr Cummings' behaviour a "disgrace".

The row stems from the Facebook data scandal, where political consulting firm Cambridge Analytica was accused of misusing private information to target voters. The firm denies wrongdoing.

Vote Leave, the main Brexit campaign group, was embroiled in the scandal after whistleblowers claimed it had employed advertising firm Aggregate IQ (AIQ) to put out targeted messages during the EU referendum in 2016.

AIQ's chief operating officer Jeff Silvester told MPs the firm had worked for Cambridge Analytica's parent company SCL but denied links with the firm itself.

In theory, parliament has powers to fine people or even imprison them but the powers are untested in recent times.

However this row could also set an interesting precedent as the committee has unsuccessfully tried to compel Facebook boss Mark Zuckerberg to give evidence.