A poll by Survation for the Daily Record found that Labour, Lib Dem and Ukip voters all showed a sizeable late swing and backed the Tories in a last ditch attempt to keep the SNP out of government.
"With all indications pointing to a hung parliament at the time, the public were very concerned that the election would result in some form of Labour-SNP deal – something which, as the chart below shows, voters from all parties were concerned about," research conclusions read.
Conservative scaremongering over the "chaos" of a deal between Labour and the SNP was pushed hard in the run up to the general election, Theresa May telling the Mail On Sunday in April that a pact between the two parties would be the "worst crisis since the abdication".
She warned: "It would mean Scottish MPs who have no responsibility for issues like health, education and policing in their own constituencies making decisions on those issues for England and Wales."
"Rightly, people in England would say 'hang on a minute, why are Scottish nationalist MPs allowed to do that?'
"There would be a very real feeling this was something people did not want to see, had not voted for and would find difficult to accept. It would raise difficult questions about legitimacy. A lot of English people would question that."
Conservative campaign directors produced adverts depicting then Labour leader Ed Miliband in the pocket of both Alex Salmond, the former first minster, and Nicola Sturgeon, his successor.
They even produced a video depicting Miliband - quite literally - dancing to Salmond's tune.
The fear of Scottish nationalists holding the English electorate to ransom was peddled by several national newspapers too.
Both The Telegraph and The Times featured headlines reading "We will hold UK defence to ransom, SNP warns", and "SNP's ransom note to Miliband", respectively.