NEW YORK, United States (AFP)— Donald Trump rose to political power touting the business acumen he says made him a fortune.

On Monday, the 77-year-old once and potentially future president is expected to testify at a civil trial in which he stands accused of fraudulently inflating those famous assets to advance his real estate empire.

Trump’s son Eric says he is “very fired up” ahead of his testimony — due to begin at 10:00 am (1500 GMT) — before New York judge Arthur Engoron, with whom the Republican has had a fractious relationship since the trial opened last month.

Just as he has insulted the judges overseeing his four criminal trials, Trump has called Engoron “unhinged” and a “Trump-hating, radical left, Democrat operative.”

Engoron has responded by slapping Trump with two fines — one for $5,000, another for $10,000 — when he ruled the onetime reality television star had violated a partial gag order imposed after he bashed the judge’s clerk on social media.

Trump has already given testimony twice in connection with this case, but both times were behind closed doors.

In excerpts from the first deposition, he called the proceedings “the greatest witch hunt in the history of our country,” and called New York state attorney general Letitia James an “out of control prosecutor.”

The bench trial — there is no jury, so the judge will decide on his own — is just one of a long line of legal troubles for the candidate who is currently the 2024 Republican presidential frontrunner, according to opinion polls.

Two of his children — Donald Jr and Eric — have testified, along with executives from the Trump Organization, a conglomerate that manages skyscrapers, luxury hotels and golf clubs around the world.

Even before opening arguments, Engoron ruled that James’ office had already shown “conclusive evidence” that Trump had overstated his net worth on financial documents by between $812 million and $2.2 billion between 2014 and 2021.

As a result, the judge ordered the liquidation of the companies managing the assets in question, such as the Trump Tower and 40 Wall Street skyscrapers in Manhattan and the opulent Seven Springs private estate in the suburbs.

That order is on hold pending appeal, but its potentially sweeping consequences highlight the high stakes for the former president.

The New York civil trial is only the tip of the legal and logistical iceberg for the candidate, as he also stares down four criminal trials set to unfold during the 2024 campaign season.

In March, Trump — who was impeached twice while in the White House, though never convicted — is expected in federal court in Washington for the start of his trial on charges that he conspired to overturn the results of the 2020 election, which he lost to President Joe Biden.

Thus far, the media circus surrounding his legal woes has not dented his popularity in the polls.

In a hypothetical 2024 rematch, Trump is even leading Biden in several key states, according to a poll released Sunday by The New York Times and Siena College.

Trump’s lawyers have rejected any notion that fraud was committed, arguing that real estate valuations are subjective, and that the banks lending to the organisation have not lost any money.

For their parts, Don Jr and Eric Trump have insisted they did not take part in preparing any of the organisation’s annual financial statements, having left that task to accountants, though prosecutors confronted Eric with emails appearing to contradict those claims.

And the parade of family witnesses will roll on as Trump’s daughter Ivanka, who no longer has an official role within the Trump Organization, is expected to take the stand, despite multiple attempts to avoid testifying.

Since Engoron established the existence of fraud before the trial even began, he must now rule on whether other financial crimes were committed, and any potential fine. Prosecutors have sought up to $250 million in penalties.