Senators say they're concerned about the growing list of vacancies in the upper chamber, as the appointment process for new members remains unclear.

There are currently nine vacant seats in the Senate, with six more senators due to retire by the end of 2026. Prime Minister Mark Carney has not appointed any senators since taking office last spring.

The federal government's website says there are also 24 vacancies on the independent advisory board for Senate appointments, the body that provides non-binding, merit-based recommendations to the prime minister.