President Joe Biden's election campaign last month outraised and outspent his challenger Donald Trump, according to disclosures published on Saturday that showed the president's coffers initially swelling even after a disastrous debate performance.

The main campaign account for Biden, a Democrat, took in $64 million in June and spent $59 million, largely on campaign ads, ending the month with $95 million in the bank, according to a filing submitted to the Federal Election Commission.

Republican Trump's main account reported raising $21 million in June and spending about $10 million, while having $128 million in cash at the close of the month.

Biden, 81, raised more than $5 million in the three days following his June 27 debate against Trump, 78, in which the president stammered throughout and failed to energetically challenge Trump's attacks, which included numerous false claims.

But this month Biden has faced a wave of calls from Democratic lawmakers to bow out of the race, and his fundraising has reportedly sagged so far in the month.

Biden and Trump have been locked in a tight race in national polls, though Trump has led in several polls in battleground states that could determine the winner of the Nov. 5 presidential election.

Since early July, 35 congressional Democrats have publicly called on Biden to end his re-election bid, with many citing his advanced age and difficulties on the debate stage. Several Biden fundraising events are reportedly on hold as some big-money donors have urged Biden to bow out.

Should Biden exit the race, control of his campaign's funds could potentially pass to his running mate, Vice President Kamala Harris, should she become the Democratic nominee. Alternately, Biden could transfer his war chest to the Democratic Party, which is already a major fundraiser for his re-election effort and reported raising $39 million with its main fundraising group June.

The main fundraising account for Trump's Republican Party raised $67 million during the month.

Trump had outraised Biden in May, when the former president's supporters stepped up donations in the run-up to his May 30 conviction on business fraud charges, a case that Trump has decried, without evidence, as politically motivated.

The largest super PAC supporting Trump, known as MAGA Inc, reported raising over $22 million during the month, including $5 million contributions by hotelier Robert Bigelow and by Linda McMahon, a former professional wrestling entrepreneur.

On Biden's side, LinkedIn co-founder Reid Hoffman gave $3 million to FF Pac, a super PAC backing the president's re-election effort, a separate filing with the Federal Election Commission showed.