Donald Trump Jr. has waded in to the Brexit endgame debate | Manny Carabel/Getty Images Donald Trump Jr: ‘Brexit and my father’s election are one and the same’ US president’s son attacks a ‘last-gasp attempt by those previously in power to cling on to what was once theirs.’

U.S. President Donald Trump's eldest son said the "establishment" is trying to "silence the voices" of those who voted for Brexit and elected his father.

Writing in the Telegraph, Trump Jr. said British Prime Minister Theresa May has "promised on more than 50 separate occasions that Britain would leave the EU on March 29 2019. She needs to honour that promise."

"But Mrs May ignored advice from my father, and ultimately, a process that should have taken only a few short months has become a years-long stalemate, leaving the British people in limbo."

Trump Jr., whose net worth is reputed to be $200 million and who is executive vice president of his father's business empire, also said that "elites control London from Brussels" and that with the Brexit deadline fast approaching, "it appears that democracy in the UK is all but dead."

Trump the younger also drew parallels between the Brexit vote and the election triumph of his father, saying they are "one and the same."

"Why is this important for us Americans? Because Brexit is an example of how the establishment elites try to subvert the will of the people when they’re given the chance.

"When my father beat the Washington establishment in a historic outcome in 2016, just a few months after the Brexit vote, we mistakenly presumed there would be a peaceful and respectful transition of power from the Democrats to the Republicans, just as there has always been in this country.

"Instead, the Democrats and deep-state operatives in our justice system have been colluding to subvert the will of the American people, with high-level officials even discussing a scheme to try to remove him from office using the 25th Amendment of our constitution.

"In a way, you could say that Brexit and my father’s election are one and the same — the people of both the UK and the US voted to uproot the establishment for the sake of individual freedom and independence, only to see the establishment try to silence their voices and overturn their mandates.

"What we’re seeing now in Washington, London and Brussels is the desperate, last-gasp attempt by those previously in power to cling on to what was once theirs in the face of an overwhelming mandate for change."