Robert Mueller filed the first charges of his investigation into Russian links to Donald Trump’s election team, indicting the president’s former campaign manager and striking a plea deal with an ex-aide who attempted to broker meetings with senior officials in Moscow.

The charges against Paul Manafort, who headed the Trump campaign from June to August 2016, and George Papadopoulos, a campaign adviser who was arrested in July but has since agreed to co-operate, mark the most serious legal threat to the president since Mr Mueller was appointed special counsel in May.

Although the 31-page indictment against Mr Manafort, who was charged along with business partner Richard Gates, focused mainly on the Republican operatives’ work in Ukrainian politics before joining Mr Trump’s team, Mr Papadopoulos has provided a detailed account of his work to secure damaging information about Democratic rival Hillary Clinton form Russian sources.