The centre-right Christian Democrats and Centre Party are reported to be the parties likely to benefit from tactical voting, with every fifth Alliance coalition voter prepared to vote for one of the smaller parties.
The Alliance voters are generally more prepared to place their vote on a party in order to keep them in parliament, with 49 percent prepared to do so, as opposed to 36 percent of the Red-Green opposition.
The Sifo survey, published in the Svenska Dagbladet (SvD) daily, shows that 52 percent of voters are not inclined to vote tactically, with six percent responding that they don't know.
The clearer political divide between the two main blocs has made tactical voting a more significant issue that in previous years, according to Stefan Dahlberg, a lecturer in political science at Gothenburg University.
"When the parties are divided into two blocs it is clear that, for example, the Moderates gain from a vote for the Centre Party or Christian Democrats," he said to SvD.
Aside from the Centre Party and Christian Democrats, the Liberals are the party that would gain the most tactical votes (19 percent) to remain in the parliament, according to the survey.
The Liberals are followed by the Green Party on 17 percent, and the Left Party on 14 percent. The fewest tactical votes would go, naturally, to the two largest parties - the Moderates and Social Democrats, with 10 and 5 percent respectively.
Only two percent of respondents are open to the possibility of voting tactically in favour of the nationalist Sweden Democrats in order to help them into parliament.