Nigel Farage attacked the BBC for fielding a “left-wing” audience in the TV debate between him, Ed Miliband and the leaders of the SNP, Green party and Plaid Cymru.
The Ukip leader was booed and jeered by members of the audience after blaming large-scale immigration for putting pressure on housing and the NHS.
He was offended by the reaction and turned on the BBC, accusing the broadcaster of selecting an unfair audience.
“There just seems to be a total lack of comprehension on this panel and indeed this audience, which is a remarkable audience even by the left-wing standards of the BBC,” he said. “I mean this lot is pretty left-wing, believe me.”
Mr Miliband told him it was “never a good idea to attack the audience," who had been chosen by an independent polling company.
Mr Farage then risked alienating the room completely when he said: “the real audience is sitting at home”.
One member of the audience who he offended was a Ukip supporter, who described Mr Farage’s attack on the BBC as “stupid” and said he was now “undecided” over who he would vote for.
He also said the Ukip leader was “stupid” to repeat claims that foreigners abused the NHS for HIV treatment. He added: “I thought Nicola Sturgeon was great. I was going to vote Ukip.”
After Mr Farage had made the allegation of bias, presenter David Dimbleby intervened to say: "This audience was carefully chosen by an independent polling organisation to represent the balance between all parties."
Mr Farage went on to blame overcrowded housing on immigration: "I just wonder, I'm curious can I get any recognition from any of you that the demand side of this equation is that a rapidly rising population due to open-door immigration, started by Ed Miliband's Labour parties in the 1990s, has directly contributed towards the housing crisis?"
Ms Sturgeon said: "We need strong controls on immigration, of course we do, and we need to make sure people do not get away with abusing the system the rest of us pay for.
"There are parts of the UK where housing and public services are under strain. I think the answer is to build more houses and invest in public services, not to scapegoat immigrants.
"I fear that the debate at Westminster on immigration is driven far too much by Nigel Farage and UKIP."
Mr Farage hit back, accusing them of unfairly targeting Ukip. "When you lose an argument in politics you resort to abusing your opponent and we have seen quite a bit of this towards UKIP recently."
In a heated exchange, Ms Wood told the Ukip leader: "So you abuse immigrants and those with HIV and then complain that UKIP is being abused."
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