On Monday, President Joe Biden sent a determined letter to congressional Democrats, affirming his “firm commitment” to continue his re-election campaign in a clear response to those within his party who have suggested he should withdraw from the race.

“The question of how we move forward has been well aired for over a week now,” Biden wrote in the two-page letter released by his campaign. “And it’s time for it to end. We have one job. And that job is to beat Donald Trump.”

“Any weakening of resolve or lack of clarity about the task ahead only helps Trump and hurts us. It’s time to come together, move forward as a unified party and defeat Donald Trump,” the president wrote.

The letter came in response to a private conference call held on Sunday, where several senior House Democrats suggested that Biden should withdraw as their party’s nominee. These calls for his resignation increased following Biden’s problematic debate performance against former President Trump on June 27.

As Congress reconvened after the July Fourth recess, there was anticipation that more Democrats might press Biden to step down. In his letter, Biden argued that replacing him as the nominee less than 120 days before the election would disregard the wishes of those who supported him in the Democratic primaries. He framed his continued candidacy as a commitment to those voters.

“Do we now say this process doesn’t matter?” the letter said, adding that Biden feels a “deep obligation” to those who cast their vote for him in the primary.

“It was their decision to make. Not the press, not the pundits, not the big donors, not any selected group of individuals, no matter how well intended. The voters — and the voters alone — decide the nominee of the Democratic Party. How can we stand for democracy in our nation if we ignore our own party? I cannot do that. I will not do that,” he wrote.