Greens MP Adam Bandt has slammed Tony Abbott's welfare crackdown as a cowardly attack on the poor driven by his recent failure in the carbon price debate.

Mr Bandt has also criticised the government's welfare reforms warning that there was a risk of a policy auction similar to law and order battles at a state level.

"This is policy on the run from Tony Abbott after his recent poor performance on the carbon price," Mr Bandt said.

"Beating up on the poor is a time honoured method of politicians in trouble."

"It will hurt people and it won't help get people into work, but it may help Tony Abbott with his flagging popularity on his backbench and with the public."

"The government is not blameless here. They have opened the door to this crackdown with their own legislation to cut people off welfare payments."

"I am worried we risk seeing a bidding war between the old parties on who can hit the poor the hardest."

"My electorate in Melbourne has high numbers of welfare recipients who will be hurt by both the government and Mr Abbott's proposals."

Mr Bandt will participate in the Inquiry into the Social Security Legislation Amendment (Job Seeker Compliance) Bill 2011. A public hearing is scheduled for Wednesday in Melbourne.