This week a sub-prime lender hiked rates for both new and existing customers by 0.75% and others are considering a similar move if they have not done so already.

This is going to hit their customers particularly hard as sub-prime borrowers are those who are charged over the odds for their loans because other lenders won't touch them.

A sub-prime lending crisis in the US has already triggered a shares' crash across the globe and raised fears of an extra interest rate hike outside the ECB cycle . . . as is already happening with subprime borrowers.

"Nobody knows the extent of the problem. The whole thing could collapse like a pack of cards, " said Michael Dowling, spokesman for the Independent Mortgage Advisers' Federation.

Already the arrival of subprime lenders . . . who are traditionally more aggressive about pursuing debts . . . has caused repossessions to double here in recent years.

And that was before the latest round of interest rate increases by both within and outside of the ECB hikes.

"My concern is that a lot of these customers were vulnerable already and this is now being compounded by increases, " said Dowling.

"They are paying for past sins and now they are paying for the mismanagement of the whole financial market."

An increase in repossessions is likely on the back of the latest increases alone . . .

which will add further to pressure on house prices. If borrowers generally are then hit with an extra rate hike on top of the ECB round of increases, then there could be repercussions for the property market.

Labour Finance spokeswoman Joan Burton said subprime lenders were a major issue. She cited examples of sub-prime salespeople canvassing door to door in local authority and affordable housing areas targeting those with low loans compared to the value of their homes.

But the reason for their low loan-to-value ratios was that they are effectively giving up to half the value of their home free of charge as these schemes aimed to make pricey homes affordable for those on low incomes.

Ms Burton said part of the problem was that sub prime lenders "are largely unregulated" and this is a problem that the Financial Regulator needs to "face up to".

"It's the elephant in the room that won't go away."