For several months now, Mr Key and Finance Minister Bill English have suggested that the operating allowance set for the next four Budgets could be "rephrased" and that tax cuts could be moved to this year.
The new operating allowance for the May 26 Budget is $1 billion; $2.5 billion for Budget 2017 and $1.5 billion each for Budgets 2018 and 2019.
Tax cuts remains a priority for the Government.
In February Mr Key said the Government's overall fiscal strategy was to keep a tight rein on spending, focus on results from public services, start to pay down debt, "and look to return any excess revenue on top of this to taxpayers".
Mr Key said today that the Government activity made up a quarter of the economy including schools, hospitals, transport, electricity and housing businesses, law enforcement and defence services.
"Our biggest contribution to the New Zealand's productivity is in running our 25 per cent better."