Washington: President Donald Trump declared on Monday that the appointment of the special counsel in the Russia investigation is "totally UNCONSTITUTIONAL!" and asserted that he has the power to pardon himself, raising the prospect that he might take extraordinary action to immunise himself from the ongoing probe.

In a pair of early-morning tweets, Trump suggested that he would not have to pardon himself because he had "done nothing wrong." But he insisted that "numerous legal scholars" have concluded that he has the absolute right to do so, a claim that vastly overstates the legal thinking on the issue.

In fact, many constitutional experts dispute Trump's position on his pardon power, an issue for which there has been no definitive ruling.

Trump's assertion that "numerous legal scholars" believe he could pardon himself ignores the one official opinion on the subject. In August of 1974, just days before former President Richard Nixon resigned, the acting head of the Justice Department's Office of Legal Counsel, Mary C. Lawton, said in a memorandum that "it would seem" that Nixon could not pardon himself.