Kamala Harris’s presidential election campaign raised more than triple the funds that Donald Trump’s did in August, according to the latest figures released by the Federal Election Commission (FEC).

The US vice-president and the Democrat National Committee (DNC) saw $257m flow into their coffers, compared with $85m raised by the former president and the Republican National Committee (RNC), continuing a towering financial fundraising advantage that has been leveraged since Joe Biden stepped away from his re-election bid in July and Harris became the party’s nominee for the White House.

The FEC’s release on Friday showed that the Democratic campaign of Harris and her running mate, Tim Walz, the Minnesota governor, and the DNC have $286m to play with in the final two months before the election on 5 November, compared with Trump’s $214m.

Harris’s cash advantage translated into significantly more spending: FEC disclosures show spending on the Harris-Walz campaign reached $174m last month, almost three times as much as the Trump campaign outlays of $61m.

Campaign and national committee combined spending shows a less extreme split. Harris and the Democrats splurged $258m last month into her sprint for the presidency, with Trump and the Republicans dropping $121m on campaign advertising and costs, $36m more than they raised that month.

Meanwhile, tech mogul Elon Musk also made his largest federal political contribution to date, giving a total of $289,100 to the NRCC, a committee dedicated to supporting Republican candidates in the US House of Representatives. The party narrowly controls the lower chamber of Congress, while Democrats have a wafer-thin majority in the US Senate and both parties are battling fiercely for control.

Despite the Harris campaign cash advantage, allowing her to blanket the airwaves with ads, opinion polls both nationally and in swing states show an extremely tight race. Both campaigns have said most of their spending was on ads, with smaller sums paying for rallies, travel and campaign staff salaries.

The Harris campaign spent more than $135m on media buys and ad production in August, FEC records showed; more than $6m on air travel; about $4.9m on payroll and related taxes; and $4.5m on text messaging. Harris’s campaign has assembled at least 2,000 aides and 312 campaign field offices across the battleground states.

The Trump campaign has not disclosed comparative details about the size of its operation. In August, it spent more than $47m on ads, alongside $10.2m on direct mail to potential voters and about $670,000 on air travel.

The financial disclosures come as an intriguing interpretation of how each candidate might get to the winning threshold of 270 electoral college votes emerged: if Harris wins the northern swing states of Michigan, Pennsylvania and Wisconsin, and North Carolina, but loses the Sun belt swing states of Arizona, Nevada and Georgia, then the 2024 election could come down to Nebraska, where five electoral college votes are assigned proportionally but there is a push by Republicans to change that to a winner-take-all system.