Ohly told Svenska Dagbladet newspaper that it was important the three opposition parties choose certain important political issues for discussion in order to work on new policies for the upcoming elections.
The parties are due to meet this week. However, Ohly stressed that they do not want to form a formal alliance as that would force Sweden into a two-party system.
At the moment, the Greens and the Social Democrats have already started discussions ahead of the next elections.
The last Social Democratic government was kept in power thanks to informal support by the Left and Green parties.