Donald Trump will deny having ever discussed former White House national security adviser Michael Flynn with former FBI director James Comey, if he is questioned about it in a sit-down interview with special counsel Robert Mueller, according to the president’s personal lawyer Rudy Giuliani.

Comey testified to senators last year that Trump told him during an Oval Office meeting that he wished Comey would drop an investigation into Flynn’s contact with Russian diplomats before Trump was sworn in as president. The conversation underpins any potential obstruction of justice claim that Mueller may bring as part of the investigation into possible collusion between the Trump campaign and Russia.

“There was no conversation about Michael Flynn,” Giuliani told Jake Tapper on CNN’s State of the Union show on Sunday. “That is what he will testify to if he’s asked that question.”

According to Comey, Trump told him “I hope you can see your way clear to letting this go, to letting Flynn go” after he was informed of an FBI investigation into contacts between Trump’s transition team and Russia.

Giuliani’s comments on Sunday appear to contradict a previous appearanceon ABC last month, in which he said Trump did not directly ask Comey to drop the investigation but offered a more nuanced, ‘Can you give him a break?’ that in his experience as a prosecutor “doesn’t determine not going forward”.

The revised account of the exchange comes as Trump’s legal team seeks to finalise the terms of a possible interview between the special counsel and the president and form an apparent pattern of publicly floating negotiating positions.

In addition to claiming there had been no conversation about Flynn, who was fired weeks after the inauguration when he was found to have misled Vice-President Mike Pence about his contacts with Russian envoys, Giuliani offered a timeline that suggests Comey revised his interpretation of the exchange.

“There was no conversation about Michael Flynn. The president didn’t find out that Comey believed there was until about, I think, it was February when it supposedly took place. Memo came out in May. And in between, Comey testified under oath, in no way had he been obstructed at any time,” Giuliani said.

“Then all of the sudden in May he says he felt obstructed. He felt pressured by that comment, ‘you should go easy on Flynn.’ So we maintain the president didn’t say that.”

The new position, if it holds, cuts through semantic complexities and differences in interpretation to what Trump may have meant, and could avoid what the president’s counsel described as a “perjury trap” for his client contained in differences of recollection.

“The president says he never told Comey he should go easy on Flynn. Comey says the president did; he put it in his memo,” Giuliani added. “So if he goes in and testifies to that under oath, instead of this being a dispute, they can say it’s perjury.”

Giuliani gave further insight into the Trump team’s thinking, softening claims that a sitting president can never be subjected to obstruction of justice complaints.

That, he said, was “far-fetched”. But he dismissed as “very questionable” the idea that a claim of obstruction of justice could be made in the context of the president firing someone who reports to him.