Senator Milne has lost about six staff members in the wake of the September 7 election, including her chief of staff Ben Oquist, and communications director, Georgie Klug.

Even though she was re-elected as Greens leader in a routine party room ballot earlier this week, the staff exodus has raised questions about support for Senator Milne.

But South Australian Greens senator Penny Wright has come out backing her leader, arguing that people have jumped to the wrong conclusion.

''I've worked with a few leaders in my time & @senatormilne is one of the best: principled, inclusive, fair, w/ a strong, intelligent vision,'' Senator Wright posted on Twitter.

''Common media "view" about meaning of staff moves in @senatormilne's office. Demonstrates how "joining the dots" can end up w/ wrong picture.''

Senator Wright was joined by Larissa Waters, who told Fairfax Media's Breaking Politics program that staff had left for a variety of reasons.

''A few of them have worked for us for about seven years and understandably feel like they need a bit of a rest,'' she said.

''It's understandable when people have families, when they want new challenges and when they have the option of a generous redundancy, given the election's happened. I think people are weighing up their options.

The Queensland senator pointed out that Senator Milne had been re-elected ''unanimously'' as Greens leader.

''I'm so proud that she's our leader,'' Senator Waters said.

Senator Milne's former communications director, Tim Hollo, has also spoken about the departures, saying the exodus of senior staff was not related to internal tension.

Mr Hollo, who left the leader's office earlier in the year, told ABC Radio on Thursday that reports of disloyalty in the office were ''really, really far from the truth''.

''In the vast majority of these cases, there's absolutely nothing going on,'' he said.

Some outgoing staff members have privately cited dissatisfaction over the direction of the party and its poor campaign strategy, Fairfax Media has reported.

In a text message, Mr Oquist said that he resigned to pursue interests in the business and community sector, but pointed to a difference of opinion with the Greens leader.

''Left on good terms but fundamental differences in opinion in strategy had emerged.''

The staff turnover comes as the Greens recorded a 4.5 per cent swing against it in the Senate and 3 per cent swing against it in the lower house, shedding more than 400,000 votes. This is despite holding on to Adam Bandt's lower house seat and picking up a new senator in Victoria.

On Wednesday night, Senator Milne said that staff had opted to take redundancies for a "range of reasons".

"It's quite common in politics after an election for people to consider whether they want to stay or not," she told ABC TV.

Some staff had indicated last year they would stay with her until the election, and some had given personal reasons for leaving, Senator Milne said.

Senator Milne has explained that her staff have the option of a "generous" redundancy given they automatically lose their jobs after every election, because of the routine leadership spill.

She denied the resignations were a vote of no confidence in her leadership. ''There's no panic or nothing to be concerned about,'' she said.''

''This is pretty normal for political offices.''

Senator Milne said there had been differences of opinion on how the office would run, she favoured a flat administrative structure while Mr Oquist wanted a more hierarchical structure.

''I wish Ben very well with his endeavours in the future,'' she said.

This comes as Greens ACT Senate candidate Simon Sheikh conceded that Liberal candidate Zed Seselja had beaten him.

While the Australian Electoral Commission is not expected to declare the final vote until next week, Mr Sheikh told ABC Radio on Thursday afternoon that he was now ''pretty certain'' that Mr Seselja would be elected.

Mr Sheikh said he would continue to live in Canberra and had ''some thoughts'' about his future.

But when asked if he would consider a job with Senator Milne, he said he had not had any conversations with the Greens leader about working in her office.

With Stephanie Anderson, AAP