WASHINGTON (NYTIMES) - A special counsel plans to finish by Sept 1 the investigation into whether US President Donald Trump obstructed the Russia inquiry, according to the president's lawyer Rudy Giuliani, who said on Sunday (May 20) that waiting any longer would risk improperly influencing voters in the mid-term elections in November.

The office of the special counsel, Robert Mueller, shared its timeline about two weeks ago amid negotiations over whether Trump will be questioned by investigators, Giuliani said, adding that Mueller's office said the date was contingent on Trump's agreeing to be interviewed. A spokesman for the special counsel's office declined to comment.

Giuliani's comments were an apparent attempt to publicly pressure Mueller amid their interview negotiations. He urged that the investigation be wrapped up as soon as possible, pointing as a cautionary tale to the revelation by former FBI Director James Comey in the last days of the 2016 presidential race that he was reopening the investigation into Hillary Clinton's use of a private email server. Comey's announcement is widely blamed by Democrats for costing her the election. The FBI found no wrongdoing.

"You don't want another repeat of the 2016 election where you get contrary reports at the end and you don't know how it affected the election," Giuliani said.

Handing in a report to the Justice Department on his findings in the obstruction case would not signal the end of Mueller's work. The obstruction examination is one piece of Mueller's broader inquiry, a counter-intelligence investigation into Russia's campaign to interfere in the 2016 presidential election. Counter-intelligence investigations are used to gather information quietly about the activities of foreign powers and their agents - sometimes for years - and can result in criminal charges.

Giuliani sought to frame the outcome of the obstruction investigation as pitting the credibility of one man against another: Trump vs Comey. The president asked Comey in the early days of the administration to end the investigation into his first national security adviser, Michael Flynn, according to contemporaneous memos and congressional testimony by Comey. The president's request is one of the main episodes Mueller is examining to determine whether Trump had criminal intent to obstruct the Russia investigation.