Trusts and HAs must prepare to be left in the lurch by their insurers on 1 January 2000, according to an NHS Executive report on the year 2000 problem.

They may also find their system suppliers have carefully safeguarded themselves against suits for recovery of damages while other suppliers have grossly underestimated the risk, say experts.

The Association of British Insurers has advised its members to remove from their all-risks cover any accidental damage caused by the bug in both computers or embedded systems - on the grounds that customers should have 'seen it coming' and taken appropriate action.

Trusts must therefore put in place contingency plans for the 'worst-case scenario' and ensure they have the budget to cover it, says the Executive's report, Year 2000 Case Studies .

This means 1998-99 budgets should include provision for replacing all atrisk critical medical equipment. The report also recommends that trust chief executives should take responsibility for year 2000 projects.

According to Graham Ross, a Liverpool solicitor working in the Y2K-Law Advisory Service, trusts will be heavily exposed to negligence claims from patients and cannot rely on reclaiming the damages from suppliers.

'I would expect that manufacturers are being closely advised by lawyers to make no admissions that could be used to establish product liability on them, ' he said. And trusts who depend on suppliers' help with the bug 'are swimming in shark-infested waters', he warned.

'The more they flap about, the greater the danger.'

Careless wording of a letter may mean the trust might later be held to have acquiesced in, or waived, a breach of contract, and could lose the right to seek damages from the supplier.

Worse, trust managers might every day be creating 'smoking gun' memos that might later have to be disclosed during legal proceedings.

'The words in such a memo could be used by a patient's lawyer to establish knowledge and foreseeability of risk, ' said Mr Ross.

NHS Executive helpline, tel: 0121-625 2711.