You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Prime_minister

Context:
In Australia, the Prime Minister is expected to step down if s/he loses the majority support of his/her party under a spill motion as have many such as Tony Abbott, Julia Gillard and Kevin Rudd.

Question:
What process signals the need for the prime minister to resign in Australia?

spill motion