Mexican diplomats are rumored to be masterminding a plan to push U.S. immigrants who have become permanent U.S. residents to become American citizens presumably so they can cast ballots against Republican front-runner and hardline immigration advocate Donald Trump.

While top Mexican officials have largely refrained from publicly discussing their strategy out of respect for U.S. sovereignty, those in the know insist that behind the scenes a movement aimed at stopping Trump has already been launched.

"This is a historic moment where the Mexican consulate will open its doors to carry out these types of events in favor of the Mexican community," Adrian Sosa, a spokesman for the consulate in Chicago, recently admitted during a "citizenship clinic" held in Dallas and attended by 250 permanent residents according to a Bloomberg article.

A month later, about 150 were on hand for another event, and at a recent gatering in Las Vegas the crowd topped 500.

Mexican-American Joel Diaz recently showed up at the Mexican consulate in Chicago with his wife and their four adult sons to register as citizens and safeguard their right to vote against Trump.

"We're very worried," said the 47-year-old evangelical pastor. "If he wins there will be a lot of damage against a lot of people here, and to us as Hispanics, as Mexicans."

Several U.S. Allies Concerned About Trump

Mexico is among a growing list of U.S. allies expressing deepening concerns over the prospect of Trump assuming the reins of the Oval Office. When he officially launched his campaign earlier this summer, Trump did so by calling Mexican immigrants killers and rapists and by vowing to erect a border wall to keep them out of the U.S.

"I'm speaking with myself, number one, because I have a very good brain and I've said a lot of things," Trump recently boasted when asked about foreign policy advisers. "My primary consultant is myself and I have a good instinct for this stuff."

Even 2012 GOP nominee Mitt Romney has expressed growing concern about some of Trump's views, and representatives from several other major capitals also appear to be growing more alarmed.

An official close to Japanese Prime Minister Shinzo Abe recently admitted a Trump presidency would be a risk for the global economy and security. Trump has targeted Japan, along with Mexico and China, as nations where the U.S. is "getting absolutely crushed on trade."

Francisco Guzman, chief of staff to Mexican president Enrique Pena Nieto, said the Mexican government is holding off on engaging Trump directly until he officially becomes the Republican nominee, should he successfully do so. Once that happens, Guzman explained, the government plans to communicate with the campaigns of the nominees in hopes of dispelling all misinformation wrongly spread about Mexico and Mexicans.

Pena Nieto Compares Trump to Hitler

Meanwhile, Pena Nieto recently compared some of Trump's fiery rhetoric to the hate-filled words of Adolph Hitler and Benito Mussolini.

Pew Research Center reports about 12 million Mexicans now reside in the U.S. Of that total, The New Americans Campaign adds, about 2.7 million are permanent residents eligible to become citizens.