Donald Trump has sued the attorney general of New York state, Letitia James, over what he claims is a “relentless, pernicious, public, and unapologetic crusade” against him, in the shape of her recent civil lawsuit against the former president and three of his adult children, Donald Jr, Ivanka and Eric. Filed on Wednesday in a circuit court in Florida, the lawsuit says James’s suit, which she announced in a dramatic press conference in September, will cause “great harm” to the company, brand and reputation of the thrice-married, oft-sued, twice-impeached and extensively legally imperiled former president. On Thursday, the New York Times reported that Trump’s own lawyers sought to stop him filing what the paper called “a tirade of a lawsuit”. The complaint begins: “Extraordinary wrongdoing requires extraordinary relief. “James has repeatedly abused her position as attorney general for the state of New York to pursue a relentless, pernicious, public and unapologetic crusade against President Trump, a resident of Palm Beach county, Florida, with the stated goal of destroying him personally, financially and politically. “Suffice it to say that these actions are contrary to both the laws of New York and Florida.” The complaint also says James’s suit “could virtually destroy [Trump’s] highly profitable Florida properties”. James accuses the Trump Organization of exaggerating asset values as a way to blindside investors and lenders. If successful, her lawsuit would bar Trump and his three named children from engaging in any executive position in New York, a provision analysts say has the potential to bring down Trump’s business empire. Trump claims no banks have missed payments from his company and says the James lawsuit would not have been filed if he were not “leading in the polls by substantial margins against both Democrats and Republicans”. Most observers expect Trump to announce a third White House run this month, after the midterm elections on 8 November and perhaps the 12 November wedding of his fourth adult child, Tiffany Trump, at his Mar-a-Lago resort. In October, claiming Trump was engaging in “fraudulent practices” and concerned that he was relocating business operations in order to avoid her suit, James asked a court in New York to freeze the former president’s assets. James has also sought an order prohibiting any real estate-related activity and a maximum fine of $250m (£224m), measures which would effectively block Trump from the industry in which he made his name. The state attorney general is also seeking to stop the Trump Organization being able to transfer or discard assets to third parties, and to secure the appointment of an independent monitor to review the company’s 2022 financial statements, in the hope of preventing accounting moves that might financially benefit the firm. In his countersuit, Trump demanded an injunction against James, to require her to cease all actions against him. He also made repeated references to James’s threats to sue him, a campaign promise when she ran for office as a Democrat in 2018, and claimed she was involved in a political witch hunt – a familiar label applied by Trump to proliferating investigations of his financial and political conduct. Trump had already filed one lawsuit against James, claiming bias. The complaint filed on Wednesday suggested more suits could follow. Reporting that Trump’s own lawyers “hotly opposed” filing the suit, the New York Times said: “The faction opposed to the suit told the Florida attorneys who drafted it on the former president’s behalf that it was frivolous and would fail, according to people with knowledge of the matter. The loudest objection came from the general counsel of Mr Trump’s real estate business, who warned that the Floridians might be committing malpractice. “Nonetheless, the suit was filed.” In a statement on Wednesday night, Trump bizarrely called the New York attorney “Peekaboo” James and labeled her state, his home until he won the White House, “one of the most crime-ridden places on earth – with murders, robberies, drug deals and every other form of crime setting records on a weekly basis”. He added: “While James does nothing to protect New York against these violent crimes and criminals, she attacks great and upstanding businesses which have done nothing wrong, like the very successful, job and tax-producing Trump Organization that I have painstakingly built over a long period of years.” For good measure, Trump’s lawsuit also took aim at a former key player at the Trump Organization: Michael Cohen, Trump’s former lawyer and fixer. Cohen spent time in jail after admitting to fraud, campaign finance violations and lying to Congress in service of Trump. He has since emerged as a leading Trump critic and testified about alleged financial malpractice at the Trump Organization. The suit filed in Florida called Cohen a “discredited, disgraced and disgruntled former attorney”.