Thanks for your question, Sophie.
A political party is an organisation that represents a particular group of people or set of ideas. Its aim is to have as many members as possible elected to the Australian Parliament so their ideas can affect the way Australia is governed.
The only limits to the number of senators and members that can come from a single political party is the number of seats in the Parliament and how many the party can win at a federal election. There are currently 76 senators and 151 members the House of Representatives, so the maximum number of representatives from any one party is 227.
While possible, it would be extremely difficult for one party to win every seat in Parliament. In the House of Representatives, the Liberal-Country Party coalition won 91 of the 127 seats at the 1975 federal election, which is 72% of all seats and the biggest by a coalition party. In 1943, the Australian Labor Party won 49 of the 74 seats (66%) which is the largest proportion by a single political party.
Prior to the 1949 election—when proportional representation was introduced—it was easier for a single party to win a large number of seats in the Senate. For example, in 1919 the Nationalist party had 35 of 36 Senate seats. However, since 1949 Senate results have been more equitable, and it is now uncommon for a single party to win a majority of seats in the Senate.