President Joe Biden reiterated to congressional Democrats he has no intention of stepping aside as their presumptive presidential nominee, urging them to unify to defeat Donald Trump in November.

“Despite all the speculation in the press and elsewhere, I am firmly committed to staying in this race, to running this race to the end, and to beating Donald Trump,” Biden wrote in a letter released by his presidential campaign on Monday as Congress returned to Washington from a two-week recess.

The president argued that bowing out of the race, as some lawmakers have urged him to do, would go against the wishes of Democratic voters who cast their ballots across the country.

“This was a process open to anyone who wanted to run ... they have chosen me to be the nominee of the party,” Biden wrote. “How can we stand for democracy in our nation if we don’t have it in our own party?”

He added: “The question of how to move forward has been well-aired for over a week now. And it’s time for it to end. Any weakening of resolve or clarity about the task ahead only helps Trump and hurts us. It is time to come together, move forward as a unified party, and defeat Donald Trump.”

Nine House Democrats have called on Biden to step aside, and dozens more have expressed concerns about his age and physical ability following his shaky debate performance against Trump last month. That number could grow as lawmakers reconvene in Washington this week.

Biden also called in to NBC’s “Morning Joe” on Monday morning, saying he had “one bad night” but that he is committed to running against Trump, citing support for him among voters on the campaign trail.

“I wanted to make sure I was right that the average voter still wanted Joe Biden. We have large crowds, enthusiastic crowds,” Biden said of his campaign events over the past week.

“The bottom line here is that we’re not going anywhere. I am not going anywhere,” he added.