Downing Street said broadcasters caused 'chaos ' with debate proposals . Branded it 'deeply unsatisfactory ' and said they should have started earlier . Ultimatum said single debate must feature Liberal Democrats , SNP and Plaid Cymru . They would debate alongside Ed Miliband , Nick Clegg and Nigel Farage . Other parties unlikely to agree , raising doubts over whether debates will happen .
Downing Street said broadcasters caused 'chaos ' with debate proposals . Branded it 'deeply unsatisfactory ' and said they should have started earlier . Ultimatum said single debate must feature Greens , SNP and Plaid Cymru . They would debate alongside Ed Miliband , Nick Clegg and Nigel Farage . Other parties unlikely to agree , raising doubts over whether debates will happen .