Treasurer Joe Hockey wants his extraordinary increase in the nation's credit limit to half a trillion dollars to be approved by both house of Parliament this week.

But in a surprise move, the Labor opposition plans to turn the tables on the once debt-averse Mr Hockey and will move an amendment to halve the proposed increase by $100 billion, taking the limit to $400 billion rather than $500 billion.

Mr Hockey told his party-room meeting in Canberra on the eve of the first sitting of Parliament in the Abbott era that the debt ceiling was the second thing to be introduced after the repeal of the carbon tax and must be dealt with immediately.