Former National Security Advisor Michael Flynn will not honour a congressional subpoena request, his lawyer said, according to the top Republican on the Senate Intelligence Committee.

Senator Richard Burr told reporters that the committee is not surprised. Congressional and federal investigators are currently probing whether Trump campaign advisers colluded with the Russian government to influence the 2016 presidential election.

“We’ll figure out on General Flynn what the next step, if any, is,” Mr Burr said, according to the Associated Press.

But later, Mr Burr backtracked his comments, Politico reported. His remarks “may have been premature”, he said, and that “there may be a day or two left” until the deadline to respond to the subpoena.

“We have not gotten the definitive answer,” Mr Burr clarified. “Michael Flynn has not cooperated with the committee up to this point.”

Mr Flynn resigned in February after it was revealed that he had misled Vice President Mike Pence and other top White House officials about his conversations with Sergey Kislyak, the Russian ambassador to the US.

Mr Flynn previously said he would testify before Congress in exchange for immunity from prosecution. However, the New York Times reported that investigators were unwilling to broker a deal with Mr Flynn.

News accounts this week said Donald Trump tried to get former FBI Director James Comey to drop an investigation into Mr Flynn, according to a memo reportedly written by Mr Comey.

The White House said that the memo is not an accurate portrayal of the conversation between Mr Comey and the president.