Greens democracy spokesperson Senator Lee Rhiannon said:
"If Bronwyn Bishop signed the parliamentary form declaring that her $5000 is a legitimate expense then it is fraud and paying back the money is not enough.
"There needs to be an Australian Federal Police investigation.
"If the AFP investigation confirms what appears to be evident then the Speaker should be prosecuted. If convicted Mrs Bishop should resign from parliament.
"If the AFP fails to investigate they are effectively politicising their own actions because of their inconsistency.