The UK government must tell MPs where it stands on 21st Century Fox's takeover bid for Sky TV before Christmas, Tom Watson demanded on Thursday (15 December).

The Labour deputy leader issued the call to the Secretary of State for Media, Culture and Sport Karen Bradley after news broke that BskyB's board agreed to a £11.7bn takeover from Rupert Murdoch's firm.

Watson, the author of Dial M for Murdoch and a former member of the Media, Culture and Sport Select Committee, grilled James and Rupert Murdoch over the phone-hacking scandal.

The episode eventually saw Murdoch close his News of the World paper. But the proprietor still owns The Sun, Sunday Times and The Times publications as part of his News UK business.

Labour and the Liberal Democrats have raised concerns of media plurality amid news of the takeover.

"Fox is attempting to finalise this deal as the Christmas break approaches – but there is still time for the government to intervene. They must express their view to parliament before Christmas," Watson said.

"When she stood on the steps of Downing Street this summer, the prime minister said to the people of this country that 'When we take the big calls, we'll think not of the powerful, but you'. This is a big call. The government needs to decide whose side it's on."

The Labour heavyweight wants Bradley to recommend James and Rupert Murdoch to media watchdog OfCom.

"To assess whether it would result in too much media power being concentrated in too few hands, and whether Rupert and James Murdoch are 'fit and proper persons' to run a broadcaster," he said.

Bradley now has 10 working days to decide whether to refer the deal to Ofcom. Sky has 22 million customers across five countries.

The Department for Media, Culture and Sports had not responded to a request for comment at the time of publication.