Alex Salmond suggested that jettisoning an attempt by the Conservatives to govern alone would allow the SNP to prop up a minority Labour administration . Alex Salmond has threatened to bring down a Conservative minority government , even if David Cameron wins more seats than Ed Miliband . The former Scottish First Minister said the Scottish National Party would vote down a Tory Queen 's Speech if it holds the balance of power after the general election . Latest polls suggest the SNP will gain dozens of seats in Scotland , depriving Labour of a majority and able to call the shots in Westminster . Mr Salmond suggested that jettisoning an attempt by the Conservatives to govern alone would allow the SNP to prop up a minority Labour administration . The Tories said it was proof the SNP would 'sabotage the democratic will of the British people ' to install Mr Miliband in Downing Street . Speaking to the New Statesman magazine , Mr Salmond said the SNP could enter a 'confidence and supply ' arrangement with Labour - under which the smaller party would agree not to bring down a minority government in return for concessions on particular priorities . But he said it was more probable that it would offer its support on a vote-by-vote basis and would make amendments to any budget put forward by Ed Balls to introduce 'progressive tax measures ' . With opinion polls suggesting the SNP are headed for dozens of gains from Labour and the Liberal Democrats north of the border , Mr Salmond - who is standing in the Gordon seat being vacated by veteran Lib Dem Sir Malcolm Bruce - would say only that he expects the party to win ' a barrel-load ' of seats at Westminster . He predicted that Lib Dems would not be ' a big factor ' in negotiations on forming the new government , as 'if the Liberals are reduced to half their MPs the last thing they 're going to be doing is going into a coalition ' . 'The surviving half will want to survive , ' he said . This would mean the SNP , unionist parties from Northern Ireland and other smaller parties would be crucial to the outcome . Mr Salmond rejected Labour 's argument that the party with the most seats after the May 7 poll will have the opportunity to form the government , insisting that the key question is which leader can command a majority in the Commons . 'The Tories would have to go straight effectively for a vote of confidence - usually the Queen 's Speech , although it could be otherwise , of course , and we 'd be voting against , ' said Mr Salmond . 'So if Labour joins us in that pledge , then that 's Cameron locked out . And then under the ( Fixed-Term ) Parliaments Act that the Westminster parliament 's passed but nobody seems to have read , you 'd then have a two-week period to form another government - and of course you want to form another government because this might be people 's only chance to form another government . ' The SNP would act to prop up a Labour government with Ed Miliband in Number 10 , even if David Cameron wins more seats . Although Mr Cameron would remain incumbent Prime Minister until a new government was formed , the Act - passed by the coalition in 2011 - would restrict his ability to call a new election in the hope of securing a decisive result , said Mr Salmond . The former SNP leader said he had 'no idea ' whether a Labour government emerging from such a process would have Mr Miliband as its leader , and suggested that he was wrong to have ruled out formal coalition with the SNP so firmly . 'If I were him , I would n't have ruled it out , ' said Mr Salmond . 'Nicola ( Sturgeon , the SNP leader ) has always said that she thought full coalition was unlikely . But she did n't rule it out : she said it was highly unlikely ... It 's still highly unlikely . ' Asked what he saw as the probable outcome , Mr Salmond said : ' I think probable would be vote-by-vote ( support for Labour ) , and possible would be confidence and supply . ' A new poll of voters in Scotland this week put Labour down to just 27 per cent , which Professor John Curtice says could leave the party with just two MPs , the same number as the Tories . Mr Salmond said it was 'bad politics ' for Mr Cameron to float the prospect of English votes for English laws on the morning after last year 's independence referendum and said it was now 'not a question of if , but when ' a second referendum on separation from the rest of the UK would take place . A Conservative spokesman said : 'Alex Salmond has confirmed he would sabotage the democratic will of the British people in order to make Ed Miliband prime minister . 'That would mean chaos for Britain , with weak Ed Miliband dancing to Alex Salmond 's tune . The only way to protect Trident , keep Britain together and safeguard the economy is to vote Conservative . '
liberal - conservative opponents says he would lead revolt against a Tory Queen 's Speech . Cameron would have first shot at forming a government after the referendum . But if legislation is passed in the Commons Labour would have a chance . Salmond mac SNP would not opt for full - blown coalition with Labour . opponents say he would ' sabotage the democratic will of the British people '