Bupa has warned that poor cost control has made the private medical insurance sector "unsustainable" and risks piling further pressure on struggling NHS services.
Speaking at a Reform event on affordable healthcare, Damien Marmion, managing director of Bupa, said customers were being driven back to the NHS by policy inflation, due to the sectors inefficiency in securing its pricing for treatments.
He said: "We are collectively paying the equivalent of more than £2,000 an hour for cataract surgery, which is more than is currently charged for complex heart and brain surgery.
"We want to change the competition rules in the market to give our customers more choice about where they can go for treatment, and ensure that the prices we pay on behalf of our members are fair and take into account all of the medical evidence.
"There needs to be greater transparency about every step of the patient journey, including the clinical outcome.
"We call on all stakeholders in the market to work in collaboration in providing healthcare that is an affordable complement to the NHS."
Professor Paul Corrigan, Health policy consultant and former adviser to the government noted that a symbiosis was necessary.
He said: "The doctors we use are the same labour, but unless we join together then the public needs in the public and private sectors will not be achieved."