In order to gain a majority to influence or control government, groups often come together in a temporary union called

In order to gain a majority to influence or Control Government, groups often come together in a temporary union called Coalition

Coalition was formed between political party to achieve a specific similar goals between those parties , whether it to influence a decision or an acceptance of a bill

To gain a majority in order to influence or control government, groups would form coalitions. 

This is a common strategy in politics and happens a lot of times when there are certain interest groups involved.