If a state has only two major political parties in the political field, it is said to have the bi-party system or the dual party system. The system is prevalent in England and the United States where only two major political parties exist. Other small political groups are there but these have no importance in political life. England has been a traditional home of the bi-party system.
Formerly the Conservative Party and the Liberal Party were dominant. Now the place of the Liberal Party has been taken over by the Labour Party and thus again its bi-party system continues. Likewise, the U.S. A. always has had the two party system. The Democrats and the Republicans now dominate the political scene.
If state has a number of political groups, the system is known as the multiple party system. Such a system prevails in France, where more than 15 political parties are in existence.
1. Legislature will form the government and the other remaining in minority will form the opposition. In other words, the bi-party system ensures a strong and stable government which can follow its programme to the extreme end. In the words, of Prof. Laski, “the two partly system enables the government to drive its policy to the statute book.”
The multiple party system, on the other hand, is responsible for the establishment of coalition governments which are the result of combination and compromise among different groups having different and very often opposite programmes and policies. Such a government cannot pursue its policy with full strength and unity of purpose. It is like a chain having many links, whereas a government of a single party is like a solid rod. Instability of the French cabinet is a historic example.
2. The government formed by a single party under the dual party system is very stable and is strong enough to face the criticism and onslaughts of the opposition confidently. The cabinet or Ministry works like a single team because all are wedded to die programme and policy of a single party.
The principle of collective responsibility which is the bed rock of parliamentarianism can be successfully followed. Moreover, such a stable government enjoying the support of a safe majority can easily continue in office for the full term of the legislature. There is very little possibility of the dissolution.
The government under the multiple-party system, however, is very unstable. A coalition government under the multiple-party system is a heterogeneous combination of diverse elements.
It may be dissolved at any moment. Governments, therefore, go on constantly changing. France, which has the multiple-party system, is notorious for constant reshuffling of governments.
The average life of a French cabinet under the third and fourth Republics was not more than eight months. Between 1871 and 1928 alone, the France had 31 Cabinets out of which as many as 28 lasted only for a term of one year. It is but natural that administration under these circumstances must be weak and inefficient. No consistent Policy can be followed. In case of constant cabinet changes, the bureaucracy rules.
3. The opposition under the dual-party system is more responsible and dignified than that under the multiple-party system. The criticism leveled by the opposition at the government is constructive because of opposition as an organized partly has fair prospects of coming into power. An organized opposition is also respected by the governments.
The reverse is the case under the multiple-party system, where the opposition consists of various groups having different principles. Such an unorganized opposition is not generally bothered by the government party.
4. The bi-party system offers a clear-cut alternative to the voters as they have to choose one out of the two parties. They are not lost in the welter of ideas. Under the multiple-party system, on the contrary, people are confused. Moreover, the voters are not sure as to which party shall form the government, because ministry is formed later on by the combination of various groups. As a result, the Cabinets are not the direct choice of the people.
5. Formation of government is simple and easy under the dual party system. The defeat of one party means the rise of the other in the legislature. The opposition party is itself a part of the state mechanism.
The leader of opposition in Canada and the U.K. is a state official with a regular salary. Maclver says that under bi-party system “there is, on the one hand, concentration of authority on the other hand concentration of responsibility and an easy means of enforcing it.” Thus constitutional crises are easily avoided.
Under the multiple party system the constitutional crises are very common because at times a decisive majority in the legislature may not be possible. It leads to political compromises and spoils system.
6. Under the bi-party system, it is easy to fix responsibility for failure of national policy. Since the Cabinet under the multiple-party system is composed of various groups, it is difficult to blame any particular group for failures and failings of the government.
Prof. Laski has beautifully summed up the merits of its bi-party system in the following words :
“It enables the government to drive its policy to the statute book. It makes known and intelligible the result of the failures. It brings an alternative government into immediate being. The group system always means that no government can be formed until after the people have chosen the legislative assembly.