New York’s attorney-general has asked a state judge to declare, even before the start of a trial, that Donald Trump committed fraud by submitting false statements to bankers and insurers and overstating his net worth by more than two billion dollars.

In filings with a state court on Wednesday in Manhattan, Attorney-General Letitia James said evidence in her civil case showed “repeated and persistent fraudulent use” by the former US president and his family business of false and misleading financial statements from 2011 to 2021.

Ms James said inflating values of more than a dozen assets by hundreds of millions of dollars established the defendants’ liability for fraud under the state’s Executive Law.

“The cumulative effect of these numerous deceptive schemes to inflate Mr Trump’s assets, and hence his net worth, is staggering,” and is “just the tip of a much larger iceberg of deception [the state] is prepared to expose at trial”, she said.

Less than an hour after Ms James’ filing, lawyers for Mr Trump and the other defendants filed their own papers seeking to end what they called Ms James’ “crusade against President Trump” and dismiss the entire case.

Citing a recent appellate court decision, they said that many of the transactions Ms James challenged took place too long ago to be reviewed in court, and said she offered no proof that anyone was harmed by the remainder.

“What she seeks to do here become the post hoc arbiter of the marketplace by interjecting her own judgment into strictly private, profitable transactions,” the defendants’ lawyers said.

“The record evidence now undermines fully her purported claims.”

Ms James filed her lawsuit last September, accusing Mr Trump of lying about property values, including for his Mar-a-Lago estate in Florida and Trump Tower penthouse apartment in Manhattan, and his own net worth.

She said Mr Trump did this to fraudulently obtain better terms on loans and insurance, and that his fraud hurt honest participants in banking, insurance and real estate markets.

The attorney-general is seeking at least $US250 million ($386 million) from Mr Trump, his adult sons Donald Jr and Eric, the Trump Organisation and others, and to stop the Trumps from running businesses in New York.

A trial before state Supreme Court Justice Arthur Engoron is scheduled for October 2.

The case is separate from four criminal indictments that Mr Trump, 77, faces as he seeks a second White House term, including two for attempting to reverse his 2020 election loss.

Mr Trump, the Republican frontrunner for the 2024 Republican presidential nomination, has denied wrongdoing in all of the cases, calling them part of a Democratic witch hunt against him. Ms James is a Democrat.

In her filing, Ms James said correcting Mr Trump’s suspect valuations would have reduced his net worth by 17 to 39 per cent each year between 2011 and 2021.

The filing said Mr Trump’s reported net worth peaked at $US6.1 billion ($9.4 billion) in both 2018 and 2019, when he was president. She said it would have been no more than $US4.2 billion ($6.5 billion) had he arranged for “full-blown professional appraisals” of his properties.

Ms James said Mr Trump should have valued his penthouse triplex in 2016 at $US119.9 million ($184.9 million) instead of $US327 million ($504 million), and valued Mar-a-Lago in 2018 at $US25.4 million ($39.2 million), based on its restricted use as a social club, instead of $US739.5 million ($1.1 billion).

– AAP