National security still on pollies' agenda

Counter-terrorism legislation and controversial changes to welfare will dominate political debate as parliament resumes in Canberra.

Prime Minister Tony Abbott is expected to outline to parliament how Australia will directly respond to the Islamic State extremists.

Cabinet will meet on Tuesday and is set to make a decision this week about Australian forces taking on a combat role in Iraq.

In the chambers of parliament, debate on social security matters is set to dominate with the Senate due to discuss a raft of controversial welfare changes announced in the May budget.