The commission has questioned the publication by the British Medical Association of scales of fees and charges to guide consultants in private practice. It began its inquiry in September last year.
In a letter dated 6 July sent to all hospital consultants, Alan Blair, assistant secretary of the commission, sets out its 'provisional' position on the supply of private medical services. It lists the issues which it says may not be in the public interest and detrimental to competition.
Mr Blair says that they have found that thousands of NHS consultants benefit from a 'complex monopoly situation' as defined by the Fair Trading Act 1973.
They found that 9,500 NHS consultants fixed more than half of their fees at, or close to, the BMA guidelines and scales set by the major health insurers.
The letter emphasised that the commission has made no decisions. But it questions the publication of guidelines by both the BMA and by Bupa and Private Patients Plan, the leading health insurers.
The provisional report then questions the extent to which these guidelines, together, lead to charges being higher than they would be otherwise and destroy regional variations in charges.
The Labour Party promised to make alternative therapy available free on the NHS in a report on complementary medicine published yesterday.