text: Ed Miliband is in league with the Scottish Nationalists and preparing to allow them to be ‘the chain to Labour’s wrecking ball’, David Cameron will say today. The Prime Minister – who last night said he would be a ‘big failure’ if he does not win a Commons majority – will unveil an analysis to show Labour and the SNP are ‘really on the same side’ and want ‘more borrowing, more debt and more taxes’. Mr Cameron will show that, since Mr Miliband became Labour leader, the SNP has trooped through the lobbies with his MPs in 91.5 per cent of Commons divisions. The SNP backed Labour in 27 out of 28 votes on welfare and 62 out of 65 on the economy. Warning: David Cameron will unveil analysis to show Labour and the SNP are 'really on thre same side' today . Labour and the SNP have ruled out a formal coalition but refused to do the same for a looser arrangement that would prop up a minority government led by Mr Miliband. The Prime Minister last night told BBC Newsnight presenter Evan Davis that he would feel he had ‘not succeeded’ if the Conservatives failed to win a majority. His intervention today will pile pressure on the Labour leader ahead of tonight’s TV ‘challengers’ debate’, in which he will square up to SNP leader Nicola Sturgeon. Miss Sturgeon’s performance in the first TV debate has seen her party surge further, breaking 50 per cent in one poll and threatening Labour with wipeout north of the border. Since Mr Miliband became Labour leader, the SNP has trooped through the lobbies with his MPs in 91.5 per cent of Commons divisions, Cameron will say . Yesterday, she suggested she would seek to hold Labour to ransom on a vote-by-vote basis, insisting: ‘It’s perfectly possible to defeat governments on issues and to change the course of governments on issues without bringing the government down.’ Even senior Labour figures have doubts over Mr Miliband’s decision to be the only leader from the main Westminster parties to appear with Scottish and Welsh nationalists, the Greens and Ukip, putting him in danger of being outflanked on all sides. A Labour source said: ‘Our best hope is that nobody watches it and it’s just a damp squib. Other than that, we’re hoping the media narrative is that Cameron was right to sit this one out, not that Ed looked like an idiot.’ Mr Cameron, launching his party’s Scottish manifesto in Glasgow, will say Scotland is the scene of a ‘massive political fight’ that could determine the future of the UK. ‘We’ve got Labour and the SNP on opposite sides – slugging it out – but if you take a step back they’re really on the same side,’ the Prime Minister will say. ‘You have a weak Labour party, who want more spending, more borrowing, more debt and more taxes. And the people who will prop them up, the SNP – who want even more spending, more borrowing, more debt and more taxes. ‘Together, they pose a clear threat to the future of our United Kingdom: a coalition of chaos. The SNP acting as the chain to Labour’s wrecking ball, running right through our economic recovery – and it will be you who pays the price.’ The Conservative analysis shows that, in 319 votes between 2010 and 2015, Mr Miliband trooped through the voting lobbies with SNP MPs on 292 occasions. Labour and the SNP (pictured, SNP leader and First Minister Nicola Sturgeon) have ruled out a formal coalition but refused to do the same for a looser arrangement that would prop up a minority government led by Miliband . David Cameron told BBC Newsnight presenter Evan Davis he will have failed as Tory leader if he does not win a majority at the next election . Labour and the Scottish Nationalists joined forces to oppose Government policies to rein in benefits and reward work. Both parties also voted against capping benefits to stop people taking home more in welfare than the average family earns in employment. Miss Sturgeon hailed tonight’s challengers’ debate as ‘another opportunity to take the SNP’s positive message on the progressive policies we believe in to people right across the whole of the UK’.
target: David Cameron will unveil analysis to show Labour and SNP 'on same side'
  He'll say since Milband became Labour leader SNP trooped through lobbies .
  SNP backed Labour in 27 of 28 votes on welfare and 62 of 65 on economy .
  Labour and SNP ruled out formal coalition but refused same for looser term .