WASHINGTON (AP) — A defiant Attorney General Jeff Sessions told Congress on Tuesday he never lied under oath about Russian interference in the 2016 election and said sleep deprivation and the “chaos” of the Trump campaign clouded his recollections of campaign contacts with Russians.

Sessions sought to explain away apparent contradictions in his public statements by portraying President Donald Trump’s campaign as an exhausting operation and said he could not be expected to remember specific encounters from more than a year ago.

“In all of my testimony, I can only do my best to answer all of your questions as I understand them and to the best of my memory,” Sessions told the House Judiciary Committee. “But I will not accept, and reject, accusations that I have ever lied under oath. That is a lie.”

Sessions, then a senator from Alabama, led a foreign policy advisory council for the Trump campaign. He has been dogged since January by his evolving explanations about his own foreign contacts during the campaign and about how much he knew of communication between Trump associates and Russian government intermediaries.

Those questions have only deepened since the guilty plea last month of George Papadopoulos, a former Trump adviser who served on the council Sessions chaired and who proposed arranging a meeting between Trump and Russian President Vladimir Putin. As well, another aide, Carter Page, told Congress in private statements that he had alerted Sessions about a meeting he planned in Russia during the campaign.

Sessions said he had no recollection of the conversation with Page. And he said that though he did not initially recall a March 2016 conversation with Papadopoulos, he now believes after seeing media reports about it that he told Papadopoulos that he was not authorized to represent the Trump campaign with the Russian government or any other foreign government.

Papadopoulos was arrested by the FBI and pleaded guilty to lying to authorities about his own foreign contacts during the campaign.

“I pushed back, I’ll just say it that way,” Sessions said under questioning, later adding that he was concerned that “he not go off somewhere pretending to represent the Trump campaign.”

Sessions insisted that his story had never changed and that he had never been dishonest. But he also suggested to the committee that it was unfair to expect him to recall “who said what when” during the campaign.

“It was a brilliant campaign in many ways,” he said. “But it was a form of chaos every day from day one. We traveled all the time, sometimes to several places in one day. Sleep was in short supply. And I was still a full-time senator keeping a very full schedule during this time.”

The oversight hearing came one day after the Justice Department said Sessions had directed federal prosecutors to look into whether a special counsel might be merited to investigate allegations that the Clinton Foundation benefited from an Obama-era uranium transaction involving a Russia-backed company.

On Tuesday, Sessions said that any such review would be done without regard to political considerations.