The Tories reported more than £1 million more in donations than Labour in the final three months of 2014 as the parties sought to boost their election war chests.
The Conservatives reported donations totalling £8,345,687 while Labour reported £7,163,988, the Electoral Commission figures showed.
The Liberal Democrats reported £3,038,500 in donations, Ukip £1,505,055 and the Green Party £248,520.
The latest regular release of donation information comes amid a bitter political row between Labour and the Tories over the tax affairs of party supporters, with Ed Miliband having accused David Cameron of being a “dodgy Prime Minister surrounded by dodgy donors”.
The total donations reported by political parties between October 1 and December 31 2014 was £20,326,862, more than £5 million higher than the previous three month period.
The total is also higher than the £17,419,277 recorded in the final quarter in 2009 when parties were preparing to fight the 2010 general election.
Labour reported a donation of £386,605 from PricewaterhouseCoopers LLP (PwC), the accountancy giant that has come under attack from one of the party’s most prominent backbenchers.
Margaret Hodge, who chairs the Commons Public Accounts Committee (PAC), said the secondment of PwC staff to work in the offices of opposition frontbenchers was “inappropriate” earlier this month.
“The Conservatives took money from PricewaterhouseCoopers when they were in opposition, the Labour Party does and probably the Liberal Democrats too. I think that’s inappropriate, I wouldn’t do it,” she told BBC Radio 4’s The World at One.
Her comments came after the PAC issued a blistering report condemning the way that PwC devised “complex strategies and contrived structures” to help big companies dramatically reduce their tax bills.
The three biggest donations were all from trade unions to Labour, with Unison handing over £1,384,289 to Mr Miliband’s party, Unite donating £1,336,570 and GMB £1,088,810.
The Union of Shop, Distributive and Allied Workers also gave £416,872 to Labour.
The Tories’ largest donation was £500,000 from Michael D Gooley, while Lord Michael Glendonbrook gave £334,000 and David J Rowland donated £322,700.
The Lib Dems received £400,000 from Max Batley while Ukip received £394,254 from Rock Services Limited.
Asked about big donations at a conference in London, Nick Clegg said: “Of course we need a party funding deal. All major parties committed in 2010 to once and for all rid British politics of the endless scandal.”
He said he was “intensely disappointed and frustrated” that after getting representatives of all parties together two years ago, a deal had not been reached, and accused the Conservatives and Labour of blocking an agreement.
Mr Clegg said that, whoever is in power after the general election, he would like to see parties say now that they will come to a new agreement that would “clean up funding once and for all”.
Conservative Party chairman Grant Shapps said: “Ed Miliband is utterly reliant on the trade unions to bail out his failing leadership, writing seven-figure cheques in exchange for writing the manifesto.
“Trade union bosses like Len McCluskey fund the party, pick the candidates, choose the leader and buy the policies.
“And that has consequences for hard-working people - a chaotic Labour Party that only offers more borrowing, higher taxes, and a less secure future for Britain.”