About half of American voters believe Special Counsel Robert Mueller's Russia probe will end in 2018 without ensnaring Donald Trump.

A new Morning Consult poll conducted for Politico found 49 per cent say it's 'likely' the president will be exonerated of any wrongdoing.

That's compared with just 37 per cent who disagree.

Mueller is helming an investigation into as-yet unproven allegations that the Trump campaign colluded with Russians to swing the 2016 election in his favor.

Forty-nine per cent of U.S. voters told pollsters last week that President Donald Trump will likely be cleared of all wrongdoing in the special counsel's Russia probe

Mueller is helming an investigation into as-yet unproven allegations that the Trump campaign colluded with Russians to tilt the 2016 election

Trump has insisted repeatedly that 'there was no collusion,' privately blaming the mess on Democrats and reporters who are intent on throwing a monkey-wrench into his administration.

He has also faulted Attorney General Jeff Sessions for recusing himself from the Russia probe – giving his political opponents a reason to insist on a special counsel to run the probe.

Wednesday's poll comes at a high-stakes political moment when Mueller is shifting his attention toward members of the president's inner circle.

He and his staff have already interviewed White House communications director Hope Hicks, former chief of staff Reince Priebus and former press secretary Sean Spicer.

Former Trump campaign director Paul Manafort faces federal charges for money laundering and conspiracy against the United States, the highest-profile Trump insider charged to date

And reports have Trump's own lawyers negotiating with the special counsel's office about the terms of a future sit-down with the president himself.

Voters are split along party lines about Trump's legal prognosis.

'Democrats and Republicans have drastically different views on whether Trump will be cleared of wrongdoing in the Russia probe led by special counsel Robert Mueller,' Kyle Dropp, Morning Consult's chief research officer said Wednesday.

'Three in four Republicans, 74 percent, say it's likely Trump will be cleared of wrongdoing in the Russia probe this year. But only 32 percent of Democrats say the same.'

Former Trump campaign director Paul Manafort already faces federal charges for money laundering and conspiracy against the United States.

Manafort's deputy Rick Gates was also indicted at the same time. Former campaign foreign policy adviser George Papadopoulos and former National Security Adviser Michael Flynn have pleaded guilty to lying to the FBI in the probe.

The Politico/Morning Consult poll was conducted on January 4-5, among 1,988 registered voters, with a margin of error of 2 percentage points.