President Trump weighed-in on the revelations Thursday, saying we are "now into the second year of the greatest Witch Hunt in American history". And at least one government informant met several times with Mr. Page and Mr. Papadopoulos, current and former officials said.
Trump attributed his claim to Andrew McCarthy, editor of the conservative National Review, who alleged that Glenn Simpson, co-founder of an intelligence firm that compiled research on Trump during the election, had testified to the Senate that the Federal Bureau of Investigation had a "human source" within the campaign.
The Watergate scandal in the early 1970s occurred following a break-in by five men at Democratic Party headquarters at the Watergate building in Washington and subsequent attempts by the administration of President Richard Nixon to hide its involvement.More news: First Look at Alex and Jo's Wedding on Grey's Anatomy
The attacks on Mueller, a Republican and former FBI director, were expected to continue as the investigation entered its second year, according to Giuliani. In 1974, justices held unanimously that a president could be compelled to comply with a subpoena for tapes and documents.
A leaked list of questions Mueller's team submitted to the White House suggests the special counsel is analyzing whether Trump obstructed justice - notably by firing Comey past year and his attempt to shield Flynn.
"If it is true that they put a spy - or two - inside the Trump campaign, it is not different from Watergate, except it is Democrats doing it to Republicans, rather than Republicans doing it to Democrats", Giuliani said.More news: FIFA's $25 Billion Revamp Plan Comes Under Fire
If Comey directed this, Giuliani said, "he should be prosecuted".
He added: "We're going to have to look into whether we can challenge the legitimacy of the entire investigation". Trump's former national security adviser, Michael Flynn, and his deputy campaign chairman, Rick Gates, have pleaded guilty and are now cooperating with the probe. The special counsel has requested an interview with Trump - a proposal the White House has thus far not accepted, as his lawyers debate the risks.
The FBI has reportedly been working in recent weeks to soften the blow if the identity of a top-secret informant who fed information to investigators early on in the Russian Federation probe is revealed.More news: Iran scolds US, Israel for unilateralism on Iran deal, embassy move