The Conservative Party has moved further ahead of Labour in raising funds to fight the 2015 general election - raking in £7.2 million in the second quarter of the year, almost double the Opposition's total.
But the Tories will be concerned by a nearly threefold leap in the cash being handed to the UK Independence Party, which raised £1.4 million in the period around its success in May's European elections.
That put it ahead of the Liberal Democrats on £1.2 million and the Scottish National Party on £1.1 million.
David Cameron has been under renewed pressure in recent weeks over wealthy donors after the inclusion of two among new appointments to the House of Lords and controversy over funds accepted from Russian oligarchs.
Electoral Commission figures showed that o ne of the biggest individual donations was the £629,570 given to Labour by property magnate Sir David Garrard, while the Tories' largest were two of £500,000 each.
Financier and party co-treasurer Michael Farmer - who was among 12 new Conservative working peers announced last week by the Prime Minister, sparking a renewed cash-for-peerages row - gave £333,500 over the period.
Of Labour's funds, £683,342 came from trade union Unison.
The vast bulk of the Ukip money was an injection of just over £1 million from Highstone Group Ltd, the company belonging to ex-Tory donor Paul Sykes who bankrolled the eurosceptic party's poster campaign.
Labour said the figures showed another £2 million had been raised by the Tories from donors who attended private dinners with David Cameron and other senior ministers - taking the total to £5 million this year.
Shadow cabinet office minister Jonathan Ashworth MP said: "When millions are flowing in from hedge funds and exclusive groups of donors, is it any wonder David Cameron stands up for the privileged few?
"Millionaires and hedge funds have been given a tax cut while hardworking families suffer from a cost-of-living crisis. David Cameron is leading an out-of-touch, hollowed-out party which has no answers to the major challenges our country faces."
The Tories said Labour had now received a total of £34 million from trade unions since Ed Miliband became leader.
Conservative Party chairman Grant Shapps said: " The figures are jaw-dropping. Apparently, it costs £1,000 an hour to hire your very own Labour leader.
"Union bosses like Len McCluskey have siphoned off £34 million from their members' pay-packets, and funnelled it into Labour's election war chest - a truly staggering amount.
"And we all know what payback they want from weak Ed Miliband: more wasteful spending, more taxes, and more debt than our children could ever hope to repay."