Joe Biden’s presidential campaign broke monthly fundraising records again in September with a $383m haul, giving the Democratic nominee a fearsome financial advantage over Donald Trump in the final weeks of the election.

The cash raised last month has left Mr Biden with a $432m war chest, his campaign said on Wednesday, as he leads Mr Trump by a wide margin in national polls with just 20 days to go until election day on November 3. Mr Biden’s haul in September beat the previous record of $364.5m, which he had set in August.

The Trump campaign and Republican National Committee have not yet released their fundraising totals for September, but their August total of $210m trailed the Democrats by some $150m.

Republicans had $325m on hand in September, the Trump campaign said last month.

Online donations have helped drive the Biden campaign and affiliated Democratic National Committee’s record fundraising totals. In September, online donors accounted for $203m of the total haul, Jen O’Malley Dillon, Mr Biden’s campaign manager, tweeted on Wednesday.

“We had 1.1m new donors last month — bringing the total to 5.5m donors throughout this campaign,” she said.

Mr Biden said in a video posted on Twitter that the average donation was less than $50.

Democrats experienced a surge in donations in September following the death of Ruth Bader Ginsburg, the Supreme Court justice who was a women’s rights pioneer.

ActBlue, a fundraising platform used by Democrats for small donations, last month reported $100m of contributions over the weekend of her death.

As Mr Biden has used his financial strength to pour vast sums into television advertising, the Trump campaign has been heavily outspent in crucial battleground states. The Democratic candidate has used his cash advantage to push into advertising in normally red Republican states, including Texas.

In the final weeks of the campaign, and with millions of Americans having already voted, Mr Trump has scheduled rallies in states he won by large margins in 2016.