"It's never stopped. No other President in history has had to put up with what I have had to", he wrote.
Until now, prosecutors have been using previously empaneled grand juries to issue subpoenas and gather evidence in an investigation that has spanned the better part of two years. While working on that case, it also will be hearing other matters.
Grand jury proceedings are confidential, and it's unclear if Vance plans to bring charges against Trump, his executives or the Trump Organization itself.
"No other President in history has had to put up with what I have had to", raged Trump, who described the investigations as "purely political, and an affront to the nearly 75 million voters who supported me in the Presidential Election, and it's being driven by highly partisan Democrat prosecutors".
The Trump Organisation did not respond to an AFP request for comment yesterday.More news: European Union to cut air links with Belarus following flight diversion incident
Mr Trump is also facing a separate criminal investigation from the New York Attorney-General's office.
Investigators suspect the Trump Organization may have artificially inflated and reduced the value of assets, particularly several properties in NY state, to either get bank loans or reduce their taxes.
Vance refuses to run for reelection and will resign at the end of the year.In other words, the Trump case Likely to be passed on to his successor in any kind of way.
Prosecutors are zeroing in on Trump's business dealing before the 2016 election, focusing on whether the Trump Organization manipulated property values to defraud banks and insurance companies. An election next month is all but certain to determine who that will be.
After subpoenaing records from Trump's accounting firm Mazars in August 2019, Vance wrangled with Trump's lawyers for their client's financial records up to the Supreme Court of the United States, twice.
In a case as complex as the Trump probe, however, Tobias argued Vance's success would be contingent on prosecutors making comprehensive presentations.More news: Local Pharmacist Ready to Complete AstraZeneca Vaccinations More
The documents are protected by grand jury secrecy rules and are not expected to be made public.
Political consultant Hank Sheinkopf said, "He will take advantage of this, Mr. Trump will. Why?" His former daughter-in-law, Jen Weisselberg, is cooperating with both inquiries.
Allen Weisserberg was summoned in a James civil investigation and witnessed twice a year ago.
This is a developing story.More news: Nyiragongo volcano has erupted