Federal prosecutors say James, who last year won a massive civil case against Trump for mortgage and tax fraud, lied while applying for a loan on a three-bedroom home in Norfolk, Virginia. She allegedly said she would use the property as her secondary residence, but instead rented the house to a family of three as an investment property.

James said the charges were “baseless” and rights groups, such as the ACLU, swiftly condemned the indictment as an abuse of power.

So did Schiff, who called the case “another vindictive prosecution” against Trump’s political foes.

The California Senator is under federal investigation for allegedly telling banks that two homes in different states were both his primary residences, so that he could supposedly receive more favourable terms on loans. He has not been charged with a crime.

Similarly Cook, the Fed governor, has been accused of claiming a vacation house as her main residence on a mortgage application. She has denied any wrongdoing and sued to block Trump from firing her, saying he is seeking her dismissal because he disagrees with her stance on monetary policy.

In his social post addressing Bondi on 20 September, Trump pressed for charges against Schiff and James, as well as former FBI Director James Comey, to be filed soon, writing that “JUSTICE MUST BE SERVED, NOW!!!”

“There is a GREAT CASE, and many lawyers, and legal pundits, say so,” he also wrote.

However, proving that any of the three officials committed mortgage fraud could be hard, if not impossible.

Borrowers have a major incentive to lie on their mortgage forms, said Clifford Rossi, a finance professor at the University of Maryland, as lower interest rates can save them thousands of dollars a year.

But, at the same time, “mistakes can be made”, he added.

For example, a person taking out a loan with their adult son or daughter as a co-borrower might mistakenly check the “primary occupant” box on the mortgage form, even though they will not live there.

“It can be as honest as a clerical error,” Mr Rossi said.

The real possibility of honest mistakes makes it difficult to prove malicious intent, he said.

In his former role as chief risk officer in Citi’s consumer lending practice during the 2008-2009 financial crisis, Mr Rossi said his team identified a “relatively high” percentage of borrowers who they believed had committed mortgage fraud.

But attorneys advised him that claims against those borrowers would be hard to prove in court. His team did not move forward with any of the cases, he said.

“You get into these issues of, did you really mean to check this box or not?” he said.

The current director of the Federal Housing Finance Agency (FHFA), Bill Pulte, could also provide a wrinkle in prosecuting the officials.

He posted about Cook’s mortgage on social media and asked the justice department to investigate the mortgage applications. Some experts have argued he violated ethics rules and that, instead, FHFA’s inspector general, an internal and nonpolitical legal watchdog, should have made the referrals.