Answer:
When a country is ruled by a single political party and the creation of other party is vetoed it's called a 1 party state or "One Party System".
Sometimes the system can become an authoritarian regime, thus people tend to think of it as the repression of the opposition due minor parties (if they exist) are usually required to agree with the dominant party by law, thereby they are sometimes considered dictatorships and their elections pondered as not legitimate.
Step-by-step explanation: