Ontario`s financial accountability officer warns of “significant risk“ that the Wynne government will not balance the provincial books by 2017-18 as promised.

Budget watchdog Stephen LeClair says there`s been a slowdown since the budget earlier this year projected growth of 4.3% in each of the next three years.

He adds growth will be just 3% at best, which he warns will make it tougher for the Liberals to stick to their budget plan to cap spending at just 0.5% annually, down from 1.4% in each of the last four years.

LeClair`s predicting the slower growth will lead to a drop in revenue of up to $1-billion from the budget forecast for the current fiscal year, making it harder to curb spending.

After looking at a number of scenarios, the financial accountability officer determined there`ll be deficits of $5.2-billion next year and $3.5-billion in 2017-18.

He believes the Liberals would have to keep spending increases to 1.4% and have growth of 3.3% to get those deficit numbers.