Are UK mortgage lenders entitled to triple their tracker rates?

The proposed doubling and tripling of Bank of Ireland's (BoI) base rate tracker from May has caused shock and outrage among its 13,500 mortgage customers in the UK. Tracker mortgage rates are meant to track the Bank of England's base rate, which hasn't moved in four years. As many consumers get to grips with how they will find the many hundreds of unexpected pounds needed each month to stave off repossession, is BoI entitled to do this? GLC's Mike Dailly believes the bank appears to be acting oppressively and may not be entitled to do this. In a guest column for MoneySavingExpert.com, he urges victims to fight back.

Are UK mortgage lenders entitled to triple their tracker rates?