Labour is raising £200,000 a week in online donations from members of the public, largely thanks to a constant barrage of targeted emails aimed at its supporters.
The party raised £407,109 from 16,629 small online donations in the first fortnight of April, according to figures supplied to BuzzFeed News, as it looked to boost its campaign funds going into the final weeks of the election.
According to Labour, more than half of the online donors to the party were giving for the first time, and a similar proportion were not party members.
The figures mean the party is on track to beat the £515,122 it raised in March from 19,226 individual online donors.
A small but substantial chunk of the funds is thought to have come from sales of vintage Labour tea towels, which insiders have described, with a slight hint of bafflement, as "astonishingly popular".
The typical online donation is £22.55, and Labour claims to have received an online donation from every constituency in Britain.
Because these are small donations worth less than £7,500, they do not need to be declared in official weekly filings to the Electoral Commission and would not normally be reported. But Labour said it wanted to release the figures to show that it is supported by ordinary people, unlike the Conservatives, "who increasingly rely on the money of hedge funds and an exclusive group of super-rich donors".
The constant emails targeted at supporters encourage small donations or offer rewards in return for donating. The money is processed by Blue State Digital, the US agency that handled Barack Obama's digital campaign, before being instantly available for Labour HQ to spend on campaigning.
Britain has previously struggled to emulate US-style crowdfunding for political campaigns, but these figures suggest it is starting to grow in popularity and could be about to make a breakthrough.
However, the sums are still small in comparison to the financial backing Labour receives from major donors – the trade unions alone gave £1.55 million in the first week of the campaign.
Unions donated £1.55m to Labour in first week of the election campaign. Unite alone gave £1m. http://t.co/ySmJseBhLe
The Conservatives told BuzzFeed News that they do not provide a running commentary on their online fundraising operations, but it is understood that during 2014 they took in 65,000 individual donations from members of public, raising £1.525 million from direct mail and online donations, in addition to £800,000 from a lottery run for party members.
Labour insists it is still well out in front on this measure, having received 40,000 small donations worth over £2.7 million to the party during the same period.