Further interest rates are forcing homeowners to consider getting out of the mortgage game / AAP Source: AAP

The Mortgage Choice survey, completed before the Reserve Bank's Melbourne Cup day decision to lift the cash rate, found 9 per cent of mortgage holders could not afford any increases to the repayments on their loans.

The survey found that the two further 25-basis-point increases widely tipped for next year would be enough for about 18 per cent of home buyers to consider selling, The Australian reports.

That's an option already taken up by Adelaide couple Sally and Martin Ojasoo, who recently sold their new home at Evanston, north of Adelaide, after struggling with $1300 monthly repayments.

The prospect of even higher rates was too much for a family budget overstretched by a five-year, 8.25 per cent fixed-rate loan taken out in mid-2008, just before interest rates crashed to record low levels in the wake of the GFC.

"I made a bad decision fixing a loan I couldn't afford," Mrs Ojasoo said.

"Then everything was pointing to even higher variable loan rates when our fixed term was due to end in a couple of years."

Breaking the fixed-term loan contract incurred a $10,000 Westpac fee, but fortunately the Ojasoos cleared about $50,000 from the sale after repaying a $24,000 credit card debt.

They plan to live mortgage-free in a kit home near Wallaroo, on South Australia's Yorke Peninsula, after paying $20,000 for a block.

Mortgage Choice questioned 1061 people, 536 of them with mortgages, about property and finance matters for this year's consumer sentiment survey.

Although respondents rated interest rate concerns second to other cost-of-living increases such as utility bills and clothing, this was before the RBA surprised markets by increasing rates - the seventh 25-basis-point rise since the previous October.

Major banks subsequently increased their marginal rates beyond the Reserve's 25 basis points.

Mortgage Choice boss Michael Russell said the findings were borne out by a subsequent doubling of calls to the group, most from anxious home buyers wanting to refinance mortgages.