THERE were questions still to be answered today about the delay in issuing a warning to members of the public who may have been exposed to the nerve agent that struck down a Russian spy, his daughter and a detective sergeant who was among the first to respond.

Public Health England issued a statement yesterday warning up to 500 people who were in the Zizzi restaurant of the Mill pub last Sunday to wash the clothes they had on at the time or double-bag them until further information was issued.

However, the statement had clearly been anticipated as early as last Wednesday when the temporary Wiltshire Police Chief Constable Kier Pritchard revealed that one of his officers, Det Nick Bailey, had been taken ill after being “part of initial response.”

He went on to add: “We are all aware that this information update will be of grave concern to the wider public and to emergency responders across the country. There will today be a wider public health message provided by Public Health England and it is of paramount importance that we will listen and follow the advice carefully.”

However it took four more days before PHE eventually issued guidance and there appeared to be some reluctance from PHE’s Chief Medical Officer Dame Sally Davies yesterday when she issued the announcement.

She said the warnings were part of a "belt and braces" approach and that her advice was the same as it had been earlier in the week that she was confident it has not harmed anyone in those locations.

She added: "however some people are concerned that prolonged long-term exposure to these substances may over week and particularly months arise to health problems.

"I'm therefore for advising as a belt and braces approach for people who were either in Zizzi's restaurant or the Mill pub from 1.30pm last Sunday until closing on Monday should clean the clothes they wore and the possessions they handled while there."

She said "this means wash clothing you haven't already, ideally in the washing machine. Any items that cannot be washed and would be normally dry-cleaned should be double-bagged in plastic until further information is available. Wipe other personal items such as phones and hand-bags and other electronic items with baby wipes and dispose of them (the wipes) in the bin. Wash other items, such as jewellery and spectacles with warm water and detergent."

There was not explanation for the delay when the team handling the incident held a press conference on Saturday. And there continues to be disquiet among the public.

Further criticism came from the city's MP John Glen, who is reported in the Daily Telegraph as saying he was frustrated: "It is an evolving investigation, so understanding what has happened and what the effects of his nerve agent are is still being worked on. But I am somewhat frustrated that Public Health England did not inform me what was going on."

He added: "I also find it slightly odd that the chief medical officer is making a statement to camera in London about this situation when the people want some reassurance here in Salisbury."