Leave of absence
Because of the provisions of section 20 of the Constitution, under which the place of a senator becomes vacant if the senator, without the permission of the Senate, fails to attend the Senate for two consecutive months of any session, the Senate grants leave of absence to senators.
Leave of absence may be granted to a senator by motion on notice, the motion stating the cause and period of absence. A notice of motion to grant leave of absence takes precedence as Business of the Senate. A senator granted leave of absence is excused from service in the Senate or on a committee. A senator forfeits leave of absence by attending the Senate before the leave expires.
It is now the practice to grant leave of absence even for short periods when there is no danger of section 20 applying. One reason for this is that the Journals of the Senate record attendance of senators and whether leave of absence has been granted.
Section 20 applies only to absence during a session, so the absence of a senator during a period when the Parliament is prorogued does not activate the section.
It is not clear whether senators should be granted leave of absence during a long adjournment of the Senate to avoid disqualification under section 20. It can be argued that, when the Senate is adjourned, it is not possible for a senator to attend in the Senate, and all senators have implied permission to be absent during the adjournment. Erring on the side of caution, however, the Senate always grants leave of absence to all senators before a long adjournment. This grant of leave of absence covers new senators whose terms of office begin during a long adjournment.