Labour and Conservative election promises on the NHS converged around a greater use of the private sector.

The Tories would have given tax breaks, and Labour - in order to reduce waiting lists - will buy blocks of operations in private hospitals.

Not only is this deeply unpopular in many parts of the NHS, it is naive and unworkable.

Unlike many European countries where there is a dual health economy, there is no 'private sector' in the UK - merely a loose, unregulated infrastructure that provides opportunities for NHS doctors to top up their incomes by moonlighting evenings and weekends.

Many clinical governance leads also agree that it can be dangerous.

A surgeon working full-time in the NHS is in no fit state to carry out a tricky operation on an NHS patient on a Monday morning if they have been working in the private sector Friday night, all day Saturday and Sunday.

All the indicators are that private medical insurance is in decline; the number of policy holders has fallen in the last 10 years, according to Laing & Buisson, and claims ratios are running at around 70 per cent of premiums.

Labour and Tory policies are destined to enrich doctors and rescue insurers while the NHS will be the poorer.

Anyway, doesn't Labour's NHS plan seek to curtail consultant activity in the private sector?

At a recent conference for private medical insurers, the delegates (most of whom were chief executives and senior managers in the sector) were asked if they would want to take over a failing NHS trust. They all ran a mile from the idea.

Private medical care is a nice little earner and an important part of freedom of choice for patients, but it has nothing to teach the NHS.

In the NHS£100 of taxpayer's money buys - warts and all -£100 of care. The same amount spent in the private sector has to reflect a transaction cost and a profit for someone.

This is not a policy, it is a fallacy.

Roy Lilley Surrey