Prime Minister Malcolm Turnbull has slammed the door shut on any increases to tax in the May budget.

After a week in which changes to capital gains tax and other tax measures to plug the widening national deficit were allowed on to the discussion table by the Coalition, Mr Turnbull on Friday ruled out a budget fix via the tax system.

"We have no plans to increase tax," he said during a joint press conference in Queenstown with New Zealand Prime Minister Bill English.

Rebuffing another intervention by his predecessor Tony Abbott, Mr Turnbull contrasted his tax record with Mr Abbott, noting that the 2016 budget delivered modest tax cuts to middle income earners to address bracket creep whereas the infamous Abbott-Hockey 2014 budget put a levy on high income earners.