Some of Canada’s biggest banks are advertising promotional ultra-low mortgage rates as the battle for customers intensifies amid a drop-off in consumer borrowing.

The Bank of Montreal (TSX:BMO) began the marketing race late Thursday with an announcement that it would offer a special discount five-year fixed rate at 2.99% for a limited time.

Not all bank customers qualify for the two-week-long promotion, which also contains a provision for a 25-year amortization period.

TD Bank (TSX:TD) answered Friday with a four-year special fixed rate at 2.99%, available until the end of February.

Royal Bank (TSX:RY) later matched that with its own four-year 2.99% rate offer, along with a seven-year special fixed rate of 3.99%.

Both are available until Feb. 29 and come with amortization periods of up to 30 years.

The other big banks, which are also struggling with lower consumer borrowing levels, could also follow suit as the banks usually move in lockstep on rates.

Fixed mortgage rates are closely tied to bond interest rates, which have fallen over worries of government debt.