The US House of Representatives Foreign Affairs Committee has issued a subpoena to compel the head of government broadcasting operations to testify next week, amid concern about editorial independence under President Donald Trump’s appointee.

Democratic US Representative Eliot Engel, the committee’s chairman, said Michael Pack backed out after agreeing to testify at a hearing on September 24. He announced the committee had issued a subpoena for testimony on the same day.

“His office failed to provide any reasonable alternative dates and his excuse for breaking his commitment is not acceptable,” Engel said in a statement.

Pack, a conservative filmmaker, has removed the heads of four of the organisations under the Agency for Global Media (AGM) umbrella – Radio Free Europe/Radio Liberty, Radio Free Asia, the Middle East Broadcasting Network and the Open Technology Fund – and replaced the bipartisan boards that govern and advise the services mostly with political appointees from Trump’s administration.

US law requires the government-funded broadcasters to operate independently and remain free from interference by any presidential administration.

Democrats had objected to Trump’s appointment of Pack, saying they feared he would see his role as forcing favorable coverage of the Republican president’s administration. Pack is an ally of conservative political activists, including Steve Bannon, once a top aide to Trump.