Private medical insurance (PMI) premiums could increase if consultants reject a new contract to allow for more evening and weekend operations today.
The government has been in talks with consultants over a new contract, which includes a 15% pay rise but a drop in overtime. It aims to cut hospital waiting times.
Consultants responded by considering to set up private, barrister-style chambers to sell their services to the NHS and insurance companies on their own terms.
Healthcare Navigator managing director Roger Hymas said this had been "brewing for a long time".
He said: "Consultants are saying they are not attracted to the NHS deal and will sell their services to insurance companies as consultant chambers."
Hymas said consultants want the prices to go up and would sell their services to the highest bidder.
"Premiums will go up," he said.
"This is a pivotal point in both public and private healthcare."
The chair of the ABI's private medical insurance committee (PMIC) and Standard Life Healthcare chief executive Mike Hall said if consultants accepted the reforms, their capacity for undertaking private work would be severely limited.