The House of Lords has held a debate on the impact that private medical insurers' reimbursement policies have on cancer patients.
Lord Crisp said: "In a nutshell, people who thought they had bought complete cancer care funding find out, sometimes in the worst of all possible circumstances, that they had bought partial cover at best.
"I was shocked when my friend told me that his insurer was setting limits on his treatment options which were not referred to in his policy documents and, even worse, proposing to change the terms of agreement after he had started to claim."
Patient care and the private medical insurers have already been subjected to scrutiny in the House of Lords.
The debate comes amidst the ongoing bitter dispute currently taking place within the private healthcare market between consultants and insurers as they clash over insurers' plans to implement fixed fee schedules and demand data consultants feel will have a detrimental effect on patient care and choice.
Lord Crisp added: "Let me be clear that not all insurers are as bad as those of my friend; when I talk to consultants, they name the same two or three which they believe are very good and the same two or three which they believe are very poor. But the reputation of all of them is damaged. The industry needs to get its act together. The Financial Services Authority needs to act and the Government need to ensure that they review this whole area."