Opposition Leader Luke Foley says he would consider supporting an increase in the GST from 10 to 15 per cent as long as the funds were used solely for health and education and to compensate low-income earners.

In an interview marking one year since his election as NSW Labor leader, Mr Foley lambasted suggestions the extra money could be used for income tax cuts as well as plugging a shortfall in health and education funding to the states as a result of cuts in the 2014 federal budget.

Premier Mike Baird and Treasurer Gladys Berejiklian have proposed lifting the GST to 15 per cent to cover the estimated $80 billion health and education funding shortfall plus compensation for low income earners.