Domino effect: Halifax's move is likely to heighten fears among other mortgage lenders.
The two increases will add more than £1,000 a year onto a typical £158,100 loan, piling the pressure onto cash-strapped homeowners.
From today, some of the lender's most popular deals, such as two-year fixed rate and tracker deals, will jump by a staggering 0.5 percentage points.
The timing of the announcement is ironic, coming the day after the Prime Minister met banking chiefs to urge them to pass the Bank of England's rate cut last week onto homeowners.
It also comes just a few days after Halifax, which controls 20 per cent of Britain's mortgage market, raised its rates last Monday.