South Australian Greens Senator Sarah Hanson-Young has criticised the move by Greens leader Richard Di Natale to dump her from the high profile immigration portfolio.

Key points: Nick McKimm replaces Hanson-Young as immigration spokesperson in Greens reshuffle

Nick McKimm replaces Hanson-Young as immigration spokesperson in Greens reshuffle Hanson-Young "incredibly sad" to lose portfolio

Hanson-Young "incredibly sad" to lose portfolio Di Natale defends move, says Greens asylum seeker policy remains 'rock solid'

On Thursday, Senator Hanson-Young was demoted to the trade portfolio after nine years as the Greens immigration spokeswoman.

Tasmanian Senator Nick McKimm, a relative newcomer who entered the Senate last year, was given the immigration portfolio in a Greens reshuffle.

"I don't agree with it, I don't accept it," she told AM.

In her first interview since being forced to change roles, Senator Hanson-Young said she was "incredibly sad" to move from an area she had put her "heart and soul into".

Senator Hanson-Young argued against losing immigration, but failed to convince Senator Di Natale.

"I fought very hard," Senator Hanson-Young said.

"I've never been one to turn my back on the men, women and children in the camps and I wasn't going to start today.

"I don't really understand Richard's decision, but I have to accept it's the decision of the leader.

"I'm ready to roll-up my sleeves and get stuck into the new portfolios that I have been given."

Policy 'remains absolutely rock solid': Di Natale

Senator Di Natale yesterday defended his decision.

"After nine years, sometimes it's time to refresh and reinvigorate the team," he said.

He praised Senator Hanson-Young's performance as immigration spokeswoman, saying she had done an "incredible job".

The Greens leader denied that he was starting to take a more moderate approach to asylum seeker policy.

"How can you be moderate when you're talking about young kids being locked up, being harmed, being abused?" he said.

"We want to shut those camps down and bring those people here.

"In terms of the policy, our policy remains absolutely rock solid."