This year's general election cost more than £112m, with the three big parties spending £40.1m on their campaigns.
Labour spent the most on election campaigning
Labour's winning campaign cost £17.94m while the Conservatives spent £17.85m and the Liberal Democrats £4.32m, says the Electoral Commission.
That means Labour spent £1.90 for every vote it won, compared with £2.03 for the Tories.
The Lib Dems got the best value at 72p per vote, although they spent more per seat won than Labour.
Advertising was the biggest cost for all three major parties.
SPENDING PER VOTE WON
Lib Dem: 72p
Scottish National Party: 47p
Plaid Cymru: 22p
Green Party (England and Wales): 62p
Each party was allowed to spend up to £19,380,000 under UK election rules.
The spending for the big three parties was up more than £15m from the 2001 poll when they spent a total of £25.1m.
George Galloway's Respect coalition also spent £320,716 in May's election, the UK Independence Party £648,397 and the Green Party £112,068.
The Ulster Unionist Party spent £251,119, the Scottish National Party £193,987 and the British National Party £112,068.
The figures show a big rise on the spending in 2001, when Labour's campaign cost £10.94m, the Conservatives' £12.75m and the Lib Dems' £1.36m.
The Department of Constitutional Affairs estimates it cost £70m to run the election.
When that cost is added to the spending for all political parties in the UK, the total for the election comes to more than £112m.
Election running costs, such as employing returning officers and officials at counts, are met by the taxpayers but parties rely on private donations to bankroll their campaigns.