Are you still in work? If not perhaps you can apply for mortgage interest subsidy.
If you are, what has changed since you got the mortgage? If income reduction then you can only try cut back all costs to the bone. If it is repayments to unsecured debt as previous reply says then you must contact them first to see if those repayments can be reduced, having said that MABS will do that for you if that is the way you want to go.