The proposed takeover of Sky by 21st Century Fox has caused a clash between the UK government and one of its most high-profile regulators.

Culture secretary Karen Bradley referred the deal to the Competition and Markets Authority (CMA) for closer scrutiny on the grounds of concern for both media plurality and broadcasting standards. The regulator, Ofcom, had recommended that the deal be recommend on plurality grounds only.

Sharon White, Ofcom’s chief executive, has defended the regulator’s conclusions, telling The Times that both issues have been examined in great detail in a “rigorous” process.

“We said on broadcasting standards there were non-fanciful concerns,” said White, “but from our review our clear advice was that these non-fanciful concerns did not justify a reference.”

The clash appears to indicate how highly politicised the takeover of Sky by Fox has become. The deal has already received regulatory approval in other European countries, including Austria, Germany, Ireland and Italy.