More than 150,000 people in the city were advised to boil their supplies because of higher than normal levels of the cryptosporidium parasite.

The warning had been in place since Saturday evening - although thousands of people in the Clydebank area did not find out that they were also affected until Monday.

The hundreds of staff who have worked non-stop for the last five days would like to thank you for your patience

Scottish Water

The warning was lifted on Wednesday following tests to the water supply.

The consultant in public health medicine for Greater Glasgow gave the all-clear at 1130BST.

Scottish Water said it would inform the public using loud halers, posters, leaflets and the media.

In a statement on its website, it also asked people to pass on the information through word-of-mouth.

The water authority said: "We have been able to lift our precautionary advice to boil your water before drinking, food preparation, brushing teeth, bathing babies and also for pets - you no longer need to carry out this procedure."

'Great relief'

The statement added: "The hundreds of staff who have worked non-stop for the last five days would like to thank you for your patience and co-operation during this difficult time for us all.

"Scottish Water apologises for any inconvenience and thanks you again for your patience."

The announcement was welcomed by Environment Minister Ross Finnie.

I am glad that the disruptive but necessary precautionary action taken by Greater Glasgow NHS Board and Scottish Water has worked

Ross Finnie Environment Minister

"It will be a great relief to people across Glasgow," he said.

"I am glad that the disruptive but necessary precautionary action taken by Greater Glasgow NHS Board and Scottish Water has worked and that people can again enjoy drinking water straight from the tap."

He said that the bodies involved would prepare reports for the NHS board.

"Ministers will see these reports and seek subsequent assurances that the lessons learnt will be acted upon," he said.

The scare followed the discovery of the parasite in supplies from Mugdock Reservoir in Milngavie, East Dunbartonshire.

Business community

Dr Jim McMenamin, chairman of the incident control team, said they were "encouraged" that no confirmed cases of illness had yet been reported.

Businesses and householders have begun calling for compensation over the disruption.

Douglas Miller of the Glasgow Chamber of Commerce said it was planning to gather the views of the businesses community then request a meeting with Scottish Water to "take matters further".

Scottish Water has set up a helpline on 0845 600 88 55. Anyone concerned about their health should contact NHS Scotland on 0800 22 44 88.