Christine Milne has survived an aborted push to challenge her leadership - but some senior Greens claim the Tasmanian senator is now ''living on borrowed time''.

Fairfax Media can reveal the departure of Senator Milne's most senior political aide, Ben Oquist, is linked to moves within the federal party to switch to Adam Bandt, her deputy.

Illustration: Ron Tandberg.

A source close to the turmoil inside the leader's office said Senator Milne had demanded the resignation of Mr Oquist, her chief of staff, after she became aware he had backed moves for Mr Bandt to mount a challenge at Monday's party room meeting.

''This is about disloyalty. Ben was trying to get rid of Christine. Adam Bandt was going to make a run for the leadership, but they called it off about an hour before party room because they didn't have the numbers,'' the source said.