The coalition has been dealt a by-election blow as the Liberal Democrats finished a woeful sixth place and the Tories were overtaken by the UK Independence Party (Ukip).
In a humiliating result for Deputy Prime Minister Nick Clegg in Barnsley Central, his party finished behind not only Labour and the Conservatives but also Ukip, the British National Party and a local independent.
There was also embarrassment for Prime Minister David Cameron as the Tories saw their vote share slump dramatically and the anti-Brussels Ukip beat them into third. However, Labour cruised as expected to a resounding victory in what is one of the party's safest seats.
Newly-elected MP Dan Jarvis, a former army major, increased Labour's majority from 11,093 to 11,771, despite a much lower turnout than in last May's general election. Only 36.5% of registered voters cast their ballots, down from 56.45% last year.
The Lib Dems - whose candidate Dominic Carman lost his deposit after securing a meagre 4.18% vote share - admitted they had been given a "kicking" while party president Tim Farron said: "It was a poor result for us. It was a poor result for the Tories. The coalition parties didn't do very well here. Surprise, surprise."
The extent of the Lib Dems' slide surpassed all predictions, with advance speculation suggesting that one or both of the BNP and Ukip might overhaul Mr Clegg's party. To be beaten also by an independent candidate with no party machine behind him - unemployed ex-miner Tony Devoy - is particularly embarrassing for the Lib Dems.
Ukip leader Nigel Farage said the result marked a major shift in the electoral landscape with the Lib Dems losing their status as the established third party. "This marks a big change for us. We are now the voice of opposition in British politics. The Lib Dems have lost that mantle," he said.
Mr Jarvis - a former member of the Parachute Regiment who has served in Iraq and Afghanistan - said Mr Cameron and Mr Clegg were paying the price for their "reckless policies". "The people of Barnsley Central are sending the strongest possible message to David Cameron and Nick Clegg," he said in his acceptance speech. "Your reckless policies, your broken promises and your unfair cuts are letting our country down."
Former Liberal Democrat leader Lord Ashdown said the party needed to hold its nerve and stick with the coalition.
"We need to keep a sense of proportion. It is not unusual for parties to take a hammering when they are in government," he told the BBC Radio 4 Today programme. "These are tough times, they are going to be difficult for the party, it is not going to be easy, this is a moment when we have to stand firm."
