The party has pledged in its platform to introduce legislation aimed at preventing the government from spending more than it's taking in.
It says the Tories would keep spending within "a fixed percentage" of the economy, so it would increase in line with economic growth.
But Hudak says it wasn't wrong to run a deficit during the economic downturn that Ontario is still recovering from.
It's a change of heart from 2009, when the Conservatives voted against a Liberal budget that laid out a plan to dive into the red ink until 2017-18.
Hudak is promising to kill Ontario's $12.5-billion deficit in 2016-17 by slashing government program spending by six per cent over four years — including cutting 100,000 public sector jobs.