British MPs renewed a demand on Tuesday to interview Facebook chief Mark Zuckerberg over a data privacy row that has rocked the social media giant, after he responded to an earlier request by offering to send one of his deputies.

Damian Collins, the chairman of the House of Commons digital, culture and media committee, said the seriousness of the allegations meant it was “appropriate” for Zuckerberg to offer an explanation himself, whether in person or via video-link.

His comments came amid renewed pressure from the European Union to disclose more details about how up to 50 million users’ data are alleged to have been taken from Facebook and used in political campaigns.