LONDON, Ont. - Prime Minister Stephen Harper has waded into the controversy over unspent funds at Veterans Affairs.

He says the $1.13 billion in lapsed funding since 2006 is part of the normal budgeting process in which departments over-estimate how much they're going to spend on programs and services.

The unspent portion is -- by law -- returned to the federal treasury and Harper says it's a practice the government doesn't intend to change.

Critics say the under-spending is part of the government's politically driven effort balance the budget -- a notion Veterans Affairs Minister Julian Fantino has described as "totally false."

It's a sensitive subject, given that the auditor general is set to release a report that is expected to be critical of the government's handling of mental health services for veterans.

In Toronto, Health Minister Rona Ambrose announced $5 million for the Canadian Institute for Military and Veteran Health Research and that comes on top of $200 million earmarked over the weekend to improve a variety of services for serving and retired soldiers.