Political parties raised a record £26.3m in donations in the run-up to May's general election.
The Conservatives attracted the most during the three months from March to June, taking in £12.3m, the Electoral Commission reports.
This was followed by Labour on £10.9m and the Liberal Democrats, who received £2m in donations.
The overall figure beats the £20.6m given in the first quarter of 2005, just prior to the previous election.
From 1 March to 30 June this year, the Scottish National Party received £277,000, while the UK Independence Party was given £256,000.
The Green Party got £54,000 and Plaid Cymru £35,000.
There were no donations registered for British National Party.
Under Electoral Commission rules, only gifts totalling £7,500 or more for a central party, or £1,500 for a constituency association, have to be declared.
The thresholds increased earlier this year from £5,000 and £1,000 respectively.
In its report, the commission reveals that, during the second quarter of this year, the Conservatives and Liberal Democrats reported receiving a total of four donations amounting to £25,806 from impermissible sources.
These were returned within the 30 days allowed.
The Conservatives also reported receiving two impermissible donations, coming to £1,275, which they did not give back within the time limit.
The commission said it was "currently discussing the matter with the party".
Meanwhile, Labour reported receiving £1,000 from an unidentifiable source, which it returned within 30 days.
Labour's biggest donors were the the unions Unite, with £1.5m, and Unison, which gave £1.1m.
For the Conservatives, the biggest donor was JCB Research, which gave the central party £750,000 and smaller amounts to several constituency associations.
The Joseph Rowntree Reform Trust gave the most to the Lib Dems - £350,000.
Labour had the highest borrowing at the end of June, of £16.6m, followed by the Conservatives on £13.1m and the Lib Dems on £1.6m.
The commission's chief executive, Peter Wardle, said: "Since 2001, we have made public details of almost 30,000 donations to political parties, with a total value of just over £433m.
"Voters have come to expect a high level of transparency about the way political parties are funded, and never more so than for the period covering a general election in the UK.
"Voters will want to see who funded political parties during the election campaign, and contributed towards this record-breaking quarter."