More than £30 million was donated to political parties in the first quarter of 2015 - the highest sum on record.
It is more than 50% up on the amount reported to the Electoral Commission in the same period ahead of the 2010 general election campaign, the independent party funding watchdog said.
Around half went to the Conservatives ( £15,404,569)m with Labour attracting £9,334,757, the Liberal Democrats £3,007,691, the Scottish National Party (SNP) £1,055,250 and Ukip £986,327.
Public funding for the period totalled £2,366,125 and parties between them owed £13,259,605 in outstanding loans - up £278,024 on the last quarter of 2014.
The biggest individual donation was the £661,250 given to the Tories by Addison Lee founder John Griffin, who had given £500,000 in each of the previous two years.
The party also received another £500,000 from Michael D Gooley, the founder of travel agent Trailfinders, taking his contribution to £1.5 million in less than 12 months.
Trade union Unite continued to be Labour's most important backer, giving £3,538,512 in the first quarter of the year - with the GMB providing another £696,680 and Unison £571,563.
EuroMillions lottery winners Colin and Chris Weir added another £1 million to their regular backing of the SNP.