Donald Trump took out his frustrations over the intensifying Russia investigation last night by lashing out at special counsel Robert Mueller, signalling a possible shift away from a strategy of co-operating with a probe that the US president believes is biased against him.

In a series of weekend tweets naming Mr Mueller for the first time, Mr Trump criticised the investigation into Russian interference in the 2016 presidential election and raised fresh concerns about the objectivity and political leanings of the members of Mr Mueller's team.

He also challenged the honesty of Andrew McCabe, the recently fired FBI deputy director, and James Comey, the bureau's former director, whom Mr Trump sacked last year over the Russia probe.

The US president's aggressive stance followed a call on Saturday by his personal lawyer for Rod Rosenstein - whom Mr Trump appointed as deputy attorney general and who now oversees Mr Mueller's inquiry - to "bring an end" to that investigation.

"The Mueller probe should never have been started in that there was no collusion and there was no crime," Mr Trump tweeted on Saturday.

Referring to Hillary Clinton and the Democratic National Committee, he continued: "It was based on fraudulent activities and a fake dossier paid for by Crooked Hillary and the DNC and improperly used in FISA COURT for surveillance of my campaign. WITCH HUNT!"

Mr Trump was referring to a dossier of anti-Trump research funded by the Democratic Party and Hillary Clinton's campaign. 'The New York Times' reported last week that Mr Mueller had subpoenaed the Trump Organisation and requested Russia-related documents.

Mr Trump had said Mr Mueller would cross a red line with such a step.

"Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and zero Republicans?" Mr Trump tweeted yesterday.

Some of Mr Mueller's investigators have indeed contributed to Democratic political candidates, but Justice Department policy and federal service law bar discrimination in the hiring of career positions on the basis of political affiliation. Mr Mueller is a Republican.

Mr Trump's attacks raised new concerns among members of Congress that he could be seeking to orchestrate Mr Mueller's firing.

"If he tried to do that, it would be the beginning of the end of his presidency," said Republican Senator Lindsey Graham, a Trump ally.

Irish Independent