Mental health and addiction services are expected to receive a massive funding boost of well over $1 billion when Grant Robertson's long-anticipated Wellbeing Budget is unveiled today.
It will also be the first Budget which reports on the reduction of child poverty, by law.
But National is planning to steal some of the Government's Budget Day thunder by revealing today how it came by secret Budget documents earlier in the week.
The Government's response to what has been called a crisis in mental health services has been slow.
Prime Minister Jacinda Ardern yesterday outlined the Government's response to the inquiry