The early results indicated Ed Milliband would face intense criticism over the next 48 hours, including over his personal performance and his appeal to working-class voters. The inquest is likely to focus on whether his campaign strategists realised early enough that UkIP posed a threat to Labour as much as to the Conservatives.
Douglas Alexander, the shadow foreign secretary and Labour election co-ordinator, insisted there were "grounds for optimism" in key target seats and that the party was well-placed to win the general election.
But the night was described as a wake-up call for the main political parties by John Healey, Labour MP for Wentworth and Dearne.
"People are angry. They are saying they aren't hearing enough of what they feel in what we politicians are saying," he said. "For me today was compounded when I was out knocking on doors and one man, a lifelong Labour voter, said to me: 'John, I'm voting for UKIP today. You all need a kicking.'"
In Labour target seats further south and east, such as Portsmouth, a strong UKIP vote was destroying the party's hopes of making more than 400 council gains.
The leader of the Labour group in Portsmouth, John Ferrett, said UKIP's performance was "causing mayhem". The party also suffered a major blow in a key election battleground after the Conservatives held on to Swindon council, days after Milliband embarrassingly failed to recognise the name of the party's group leader in the borough.
But the man in question, Jim Grant, insisted Milliband's gaffe had not had an impact on Labour's disappointing showing in the Wiltshire town.
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