New suits are being issued

The relevation comes comes as the government cancels the only large scale simulation of a biological attack for emergency services to practise procedure.

Staff discovered the problem while taking part in exercises to simulate washing down people who are exposed to chemical or biological agents in an attack.

Dr John Heyworth, president of the British Association for Accident and Emergency Medicine, said that when the problem was raised, NHS staff had received instructions about how to plug leaks with tape.

"That wasn't a great confidence booster. It was alarming that that was the sort of measure required," he said.

We have taken very clear steps and action to get rid of problems John Hutton

Health Minister John Hutton told the BBC Today programme said that new suits were being issued.

However, he acknowledged that they would not all be in place for around two months.

In the meantime, modifications were being made to existing suits, said Mr Hutton.

These include an extra section over the boot to let water run off.

Unacceptable delay

He admitted that it was unacceptable for health authorities to tell staff to fix leaks with tape, as some have done.

Mr Hutton said that the Department of Health had been alerted to the problem with bio-chemical suits by several ambulance trusts last December, and had immediately introduced a scheme to modify and replace them.

He said: "We are now in the middle of a programme of replacing these suits with a new modified version.

"It will take a few more months to complete this programme, but we haven't just sat back and waited for new suits to arrive.

"We have made modifications to existing suits. It is not ideal, but they are safe.

"Some of the new suits have already been distributed to ambulance trusts. It will take a couple more months to have that complete.

"Our people who are acting in the public interest and putting themselves in harm's way, we are not going to expose them to unacceptable levels of risk.

"That is why we have taken very clear steps and action to get rid of problems caused in the manufacture of these suits."

Every primary care trust and hospital across the NHS has developed plans for dealing with possible biochemical incidents.

Mr Hutton said these were regularly being tested in emergency simulation exercises.

However, he confirmed that a major exercise in London had been cancelled, because of uncertainty over whether firefighters currently embroiled in a pay dispute would be willing to take part.