The Australian Greens have condemned the funding cuts to indigenous legal aid services, which will see the peak body NATSILS close its doors in June.

Spokesperson for legal affairs Senator Penny Wright said the National Aboriginal and Torres Strait Islander Legal Service advocacy was crucial to addressing shocking levels of indigenous incarceration.

"More than one in four prisoners are Aboriginal, despite making up only a fraction of our population. Too many are in jail because of inadequate legal understanding and representation," Senator Wright said.

Prime Minister Tony Abbott must urgently clarify if he intends to reverse his party's election promise to make multi-million dollar cuts to indigenous legal aid, say the Australian Greens.

The Attorney General's Department last night confirmed frontline services could not be isolated from the $42 million cut to indigenous legal aid funding under questioning from Senator Rachel Siewert and Senator Penny Wright.