Hundreds of additional former federal prosecutors have signed onto a statement asserting that President Trump would have been indicted for obstruction of justice were he not currently serving as president.

The open letter organized by the nonprofit group Protect Democracy had roughly 400 signatures when it was initially posted Monday afternoon on Medium. The letter neared 700 signatures as of Tuesday afternoon.

Among the new signatories are Sen. Richard Blumenthal (D-Conn.), a former U.S. attorney for the District of Connecticut, and Rep. Kathleen Rice (D-Mass.), a former prosecutor in the U.S. attorney's office in Philadelphia. Both lawmakers have been critical of Trump.

The letter claims that were it not for Justice Department guidance stating that a sitting president cannot be indicted, Trump would have been charged with obstruction of justice based off the evidence laid out in special counsel Robert Mueller's report.

The former federal prosecutors point to Trump's attempt to direct former White House counsel Don McGahn to fire Mueller, as well as other actions to limit the scope of the special counsel investigation, as being sufficient evidence to obtain an obstruction of justice charge.

"Each of us believes that the conduct of President Trump described in Special Counsel Robert Mueller's report would, in the case of any other person not covered by the Office of Legal Counsel policy against indicting a sitting President, result in multiple felony charges for obstruction of justice," the letter reads.

Mueller declined to make a decision on whether to charge Trump with obstruction of justice, a move that Attorney General William Barr said caught him by surprise.

Barr said he and Deputy Attorney General Rod Rosenstein reviewed the evidence laid out by Mueller in the report and determined that it was not sufficient to bring forward an obstruction charge.

But some Democrats have disputed that point, and have instead accused Barr of acting to protect Trump.