WASHINGTON Federal prosecutors investigating former President Donald Trump s actions leading up to and during his mobs assault on the Capitol will get access to key evidence after his former vice president decided not to pursue an appeal to avoid testifying.

Mike Pence aide Devin OMalley said that a judges ruling had agreed with him on the key issue that Pence had objected to regarding his role on Jan. 6 itself as presiding officer of the Senate. Having vindicated that principle of the Constitution, Vice President Pence will not appeal the judges ruling and will comply with the subpoena as required by law, OMalley said.

Pence had originally said he would take his battle to quash the grand jury subpoena to the U.S. Supreme Court if necessary. But a week ago, he said that he was pleased that James Boasberg, the chief judge of the U.S. District Court in Washington, D.C., had agreed with his argument that the speech and debate clause in the Constitution applied to him in his role as president of the Senate.

Prosecutors main interest in Pences testimony, though, is not in his dealings with members of Congress. Rather, it is in his interactions and conversations with Trump and his aides, who had been pushing him for weeks to use his role as presiding officer at the election certification ceremony on Jan. 6, 2021, to award Trump a second term, even though he had lost his re-election bid to Democrat Joe Biden two months earlier.

Trump attempted to claim executive privilege to prevent Pence from revealing that information, but Boasberg rejected that argument in his still-sealed ruling.

It is unclear whether Trump will appeal Boasbergs ruling to keep Pence from testifying. Trumps staff did not immediately respond to a HuffPost query, but his lawyers a week ago filed a similar appeal in an attempt to prevent other senior White House aides, including former chief of staff Mark Meadows, from having to answer questions before the grand jury. That appeal was denied Tuesday.

Norm Eisen, a former White House lawyer in the Obama administration who worked with House leaders on Trumps first impeachment for extorting Ukraine, said Pences testimony would be of the utmost importance to special counsel Jack Smith.

He is a critical firsthand witness to Trumps statements as the attempted coup evolved, Eisen said. The most important testimony that Pence has to offer begins on Dec. 5, when Trump first raised the idea of challenging the Electoral College with him, and rolls through the remainder of that month and into Jan. 6 itself.

While Boasbergs ruling, according to Pence and others, says Pence is not required to reveal his interactions with members of Congress, it does not shield him from discussing Trump and other executive branch officials.

Pence will likely be required to testify about everything outside his official duties in Congress on the 6th, so all of those conversations will likely be up for grabs, Eisen said.

Trump and his inner circle began planning to use fraudulent slates of Trump electors well before the Electoral College met on Dec. 14, 2020, to ratify Bidens victory. Indeed, that very morning, senior Trump White House adviser Stephen Miller appeared on Fox News and boasted of how pro-Trump slates of alternate electors were being chosen as he spoke so that Congress would have competing slates from key states, handing Trumps allies the opportunity to give him a second term.

Trump and his aides began pressuring Pence to go along with the scheme in early December and ramped up their efforts after Christmas, according to former Pence advisers, and testimony revealed at the House Jan. 6 committee hearings.

The pressure campaign culminated in Trumps Jan. 6 pre-insurrection speech near the White House, where he again called on Pence to do as he had demanded, even though Pence had already told Trump that he had no constitutional authority to do so. That afternoon, Trump attacked Pence for not having the courage to do what Trump wanted, and his mob responded by storming into the Capitol en masse.

Four of Trumps followers died on Jan. 6, as did five police officers in the following days and weeks. Another 140 officers were injured, and the Justice Department is prosecuting over a thousand rioters, with at least hundreds more cases expected.

Despite this, Trump is running for the presidency again and is currently leading his rivals for the GOP nomination in polls. And while he initially denounced those who committed violence on Jan. 6, he has more recently embraced their actions and has promised to pardon them if elected. At a recent rally, he even featured a recording of Jan. 6 detainees the vast majority charged with assaulting police officers singing The Star-Spangled Banner interspersed with Trumps reading of the Pledge of Allegiance.