Gordon Sondland, US ambassador to the EU, said he carried out a campaign to press Ukraine to open politically motivated investigations at the direction of Donald Trump, and that other top officials, including secretary of state Mike Pompeo, were “in the loop”.

Mr Sondland on Wednesday became the first member of Mr Trump’s inner circle to say Kyiv was told to announce the investigations demanded by the US president to secure a phone call and White House meeting for Ukrainian president Volodymyr Zelensky.

“Members of this committee have frequently framed these complicated issues in the form of a simple question: Was there a ‘quid pro quo?’,” Mr Sondland told the House intelligence committee, which is leading the public phase of the presidential impeachment inquiry.