Quinn-healthcare has confirmed that the majority of its 400,000 members will be affected by an 18% increase in prices from January 2008.
The insurance group said its new pricing plans remained competitive and reflected the cost of doing business here.
However the VHI has accused the Quinn group of being 'misleading' and warned its customers to beware.
Earlier today Quinn-healthcare, which took over from BUPA last February, announced a range of price increases.
The company stated the average increase would be 3% for an individual and 5% for family plans.
These marginal increases will affect four out of ten of the healthcare plans.
But alongside these charges, the company has decided to scrap all discount schemes and charge customers paying monthly an extra 3% service charge.
These measures will affect the vast majority of the company's 400,00 customers. Most joined through a group or online scheme, availing of a 10% discount.
From January that discount will no longer apply and, combined with the monthly debit fee, most customers can expect a total price hike as high as 18%.
Tonight, Quinn Insurance said it was not penalising customers, but introducing measures already accepted in the motor and home insurance sectors.
Colin Morgan, general manager of Quinn Insurance, said the price hikes reflected the cost of insurance claims and risk equalisation but stressed the company remained cheaper and more competitive than others.
In response, the VHI tonight warned customers to 'beware' and said Quinn-healthcare was not being transparent with its price increases.