1. The two parties are of reasonably equal electoral strength. This means that one of the parties could be in power at one time and at another time could be displaced by the other party.
2. Ideologically and in terms of their programmes, the two parties are too far apart.
3. There is a marked feature of tolerance between parties. The activities of the ruling party allow the existence of the opposition.
4. There are two major alternative programmes from where the citizens can choose at a given time.