The departure of Karen Bradley as UK Culture Secretary could cause significant delays to 21st Century Fox's £11.7 billion acquisition of Sky.
Bradley was named Northern Ireland Secretary yesterday as part of a government reshuffle, having been Secretary of State for Digital, Culture, Media and Sport since July 2016.
Second-in-command Matt Hancock has been appointed to replace her.
The deal, which Bradley referred to the Competitions and Markets Authority (CMA) in September, was not expected to be completed until at least June 2018, but this latest development could see finalisation delayed until later in the year.
At the time, Bradley told parliament she was minded to refer the deal to the competition regulator on the grounds of media plurality and on the grounds of commitment to broadcasting standards.
A final CMA report was to be sent to Bradley by March 2018. The proposed takeover dates back to December 2016, but has been delayed by two investigations, first by media and telecoms regulator Ofcom and now the CMA.