Premier Mike Baird's proposal to lift the GST to 15 per cent would still fall billions of dollars short of the revenue that modelling suggests is needed to cover escalating national healthcare costs.

Preliminary modelling Mr Baird is due to present to Prime Minister Tony Abbott's meeting of state and territory leaders on Wednesday shows lifting the GST to 15 per cent – without broadening its base – would raise an extra $36 billion by 2020.

Weighing into the debate: NSW Premier Mike Baird. Credit:Edwina Pickles

However, after households earning below $100,000 are fully compensated for the rise and those earning between $100,000 and $155,000 receive back half the increase, the revenue boost is $18 billion.