The federal government posted a budgetary deficit of $4.3 billion from April to August.
In its monthly fiscal monitor, the Finance Department says this compares to a surplus of $3.9 billion during the same period of the 2022-23 fiscal year.
Government revenues increased $2.4 billion, or 1.4 per cent, largely due to higher interest revenues and other non-tax revenues.
Program expenses excluding net actuarial losses increased $7.4 billion, or 4.8 per cent.
Public debt charges grew by $4.1 billion, or 27.7 per cent, largely due to higher interest rates.
Net actuarial losses decreased by $0.9 billion, or 22.7 per cent, compared to the same period last year.