- No party may cooperate with, or take the support of, the Sweden Democrats
- Without the Sweden Democrats no minority coalition can survive.
- Any coalition must command a majority (175 seats)
- If the Left Party is included in any way then no party from the right of the divide will participate
- The Moderates or any parties to the right of the Moderates, will not participate if the Environmental Party (MP) is included
- The Centre Party may participate with a mildly left coalition provided it does not include the Left party
Currently the Swedish Parliament has 349 members from 8 parties.
Social Democrats – 113, Moderates – 84, Sweden Democrats – 49, Environment Party – 25, Centre Party – 22, Left Party – 21, Peoples Party – 19, Christian Democrats – 16.
Following these rules and assuming that the current composition of parliament is not much changed after the extra election in March 2015, only two possible majority coalitions are arithmetically possible:
- A Grand Coalition of the Social Democrats and the Alliance group of parties, or
- A grand coalition of the Social Democrats and the Moderates
The simple rule is that it has to be a coalition of the middle ground. That excludes the Sweden Democrats on the extreme right and the Left and the Environmental parties on the extreme left.
One consequence is that no matter what majority coalition is formed, the Sweden Democrats will be the largest party in opposition.