Donald Trump pressured top justice department officials to falsely declare that the 2020 election was corrupt and launch investigations into discredited claims of fraud as part of an effort to return him to office, the House January 6 select committee will say on Thursday.

The panel investigating the Capitol attack is expected at its fifth hearing to focus on how Trump abused the power of the presidency to twist the justice department into endorsing false election claims – and potentially how the Republican congressman Scott Perry sought a pardon for his involvement.

The finer details of the hearing were outlined to the Guardian by two sources close to the inquiry who spoke on the condition of anonymity because they were not authorized to reveal details ahead of the hearing. They cautioned that the details might still change.

Among the points the select committee is expected to cover include how Trump pursued a relentless campaign against the leadership of the justice department to more aggressively investigate debunked claims of fraud, and threatened to fire them when they refused.

The foundation of that effort, extraordinary even by the standards of the Trump presidency, culminated in a 3 January 2021 meeting at the White House where Trump almost appointed a loyalist as acting attorney general until the leadership warned of en masse resignations.

At that contentious meeting, Trump was about to move ahead with a plot to replace the acting attorney general, Jeffrey Rosen, with Jeffrey Clark, a justice department official sympathetic to claims of election fraud.

The former president only relented when he was told by Rosen that the justice department leadership would resign – and the White House counsel, Pat Cipollone, said he and his deputy, Pat Philbin, would also quit if Trump followed through.

Trump’s proposed plan amounted to a “murder-suicide pact”, Cipollone is understood to have said, according to a participant at the meeting who testified to the Senate judiciary committee that issued an interim report last year.

The select committee is also expected to examine the fraught weeks leading up to that moment, and the growing fear inside the justice department that Trump might drag them in to overturn the election results.

Perry introduced Clark to Trump, the interim report found. The panel is expected to shed new light on that at the hearing led by Congressman Adam Kinzinger, as well as how Perry sought a presidential pardon days after 6 January.

The hearing is expected to be the select committee’s final one in June – there will be at least two more hearings next month but probably not before 12 July when the House returns from recess – and will probably build on the interim report.

In doing so, the select committee is likely to relive other key moments: a 27 December 2020 call in which Trump pressured Rosen and his deputy, Richard Donoghue, to declare the election corrupt; Trump’s push to get Clark to get Rosen to open investigations into fraud.

Rosen and Donoghue will testify at the hearing, as will Steven Engel, the then assistant attorney general for the Office of Legal Counsel, the select committee has said. Clark invoked his fifth amendment protection against self-incrimination in a closed-door deposition.

“Just say that the election was corrupt and leave the rest to me” and congressional allies including the Republican congressman Scott Perry, Trump said on the call, according to notes taken by Rosen.

The former president also spoke multiple times with Clark about pushing his superiors to send Georgia officials a letter that falsely claimed the justice department had identified “significant concerns that may have impacted the outcome of the election”.

When Rosen and Donoghue refused, the interim report found, Trump considered firing them. On 2 January 2021, Trump appeared to coerce Rosen to send the letter, first suggesting he could dismiss Rosen, and then saying he would not fire Rosen as long as he sent the letter.