US President Donald Trump has broken his silence on Twitter after James Comey’s explosive testimony to accuse the former FBI director of perjury.

Trump, who had not posted on Twitter as Comey accused his administration of spreading “lies” on Thursday, struck back with a tweet early yesterday morning in which he said: “Despite so many false statements and lies, total and complete vindication ... and WOW, Comey is a leaker.”

Talking under oath on Thursday, Comey laid bare on Capitol Hill months of distrust of the president, suggesting Trump had fired him to interfere with the probe of Russia’s ties to the Trump campaign.

The ex-FBI boss led one of several Russia inquiries before he was sacked.

Comey also said the president pressured him to drop an investigation into former national security adviser Michael Flynn.

At his first congressional appearance since being fired, Comey revealed that he had orchestrated the public release of information about his private conversations with the president in an effort to further the investigation.

Meanwhile, a senior Russian politician dismissed his testimony as insignificant. Alexei Pushkov, chairman of the information policy committee at the upper chamber of the Russian parliament, said Comey’s testimony was a “big bubble” and that it “will not help Trump’s adversaries to start impeachment proceedings”.

Russian officials have denied any role in hacking attacks on the Democratic National Convention and voter-registration databases.

Comey’s statement has deepened questions about the basis for his May 9 dismissal and about whether the president’s actions constituted obstruction of justice.

Trump’s private lawyer, Marc Kasowitz, seized on Comey’s admission he had told the president on multiple occasions that he was not personally under investigation and maintained the testimony made clear that Trump “never, in form or substance, directed or suggested that Comey stop investigating anyone”.

Kasowitz also jumped on Comey’s revelation he had released details of his private conversations with Trump, casting the former FBI director as one of the “leakers”

set on undermining the administration.

Still, there was no doubt Comey made for a challenging adversary.

“It’s my judgment that I was fired because of the Russia investigation,” he said on Thursday.

“I was fired in some way to change, or the endeavour was to change, the way the Russia investigation was being conducted.

“That is a very big deal, and not just because it involves me.”