Rupert Murdoch's £11.7 billion bid to take full control of Sky may be referred to the competition regulator for further investigation, the Culture Secretary has said.
Karen Bradley has been assessing thousands of responses following a consultation about the proposal from 21st Century Fox.
After weeks of deliberation, Ms Bradley confirmed in Parliament she intends to ask the Competition and Markets Authority (CMA) to conduct a fuller investigation into the bid on the grounds of media plurality, and other issues.
Bradley confirmed her intention to refer the bid to the CMA on the grounds of media plurality.
This means she has concerns about the possibility of the bid contributing to a lack of diversity of viewpoints and content across the media.
On broadcasting standards, Ms Bradley said Ofcom had been asked to provide further advice before telling MPs: "I have taken careful account of all relevant representations and Ofcom's advice and have today - as required by the legislation - written to the parties to inform them I am now minded to refer the merger to the CMA on the grounds of genuine commitment to broadcasting standards."
Ms Bradley said Ofcom had concluded concerns over corporate governance failures do not warrant a referral, adding: "I agree that corporate governance issues at Fox raise non-fanciful concerns, but in my view it would be appropriate for these concerns to be considered further by the CMA.
Ms Bradley said the legal threshold to refer a bid to the CMA is low, and she has the power to do so if she believes there is a non-fanciful risk of a merger operating against specified public interests.
Sky shares fell 3% after the announcement.
Shadow Culture Secretary Tom Watson said he welcomed Ms Bradley's decision and praised her as a "good 'un".
I think it's the first time a minister in the current Government has ever stood in the way of what the Murdochs want, and frankly not before time, so well done, and as they say in the Black Country, she's a good 'un. She's done everything we asked her to do. Or almost everything. >
Mr Watson however criticised Ofcom for not going far enough on the test of whether Sky was "fit and proper" for the merger, "despite clear evidence of impropriety and failure of corporate governance both at 21st Century Fox and at News Corporation".