A former aide to Donald Trump declared on live television that he was refusing to co-operate with a subpoena requiring him to hand over campaign information to the investigation into Russian election meddling.

Sam Nunberg, who helped launch Mr Trump’s White House run before being fired when racist comments on his Facebook page were exposed, conducted a string of interviews in which he said he would refuse to help Robert Mueller’s probe of the 2016 election.

And he made a number of embarrassing claims – suggesting Mr Trump would have endorsed Hillary Clinton if he had not won the Republican nomination, and that Mr Mueller may have evidence of the president’s wrongdoing.

He said collecting emails other communications with key Trump advisers, including Steve Bannon and Roger Stone, would be too much effort.

“They want me over at the grand jury. Screw that. Why do I have to go?” he told CNN.