Suspended ATSIC chairman Geoff Clark will take his fight to be reinstated to the Federal Court.

Indigenous Affairs Minister Amanda Vanstone asked the suspended chairman to show cause why he should not be sacked.

Today she said she was not satisfied he should be reinstated and has imposed a new suspension because of a conviction of obstructing police.

"I've taken what I think is the appropriate step at this time to suspend Mr Clark and I don't think it's helpful to try and look into the future and see what might happen after that," she said.

Mr Clark was suspended after he was charged over his involvement in a brawl at a hotel in the Victorian city of Warrnambool in 2002.

But Mr Clark believes the minister does not have the power to sack him and has taken his case to the Federal Court.

"There is a bigger agenda here, that is to silence the ATSIC chairman, the voice of Aboriginal people," he said.

The case will be heard in Melbourne next Wednesday.