Unison are one of the UK's largest trade unions

Unison said that about 600 social care staff at Glasgow City Council could take part in the action on Monday.

Union officials said the dispute was focussed on a disagreement with the council over job grading.

A council spokesman said the authority would not give in as the union was "trying to force the council's hand".

The affected staff manage the cases for children at risk, vulnerable adults and offenders and are accountable to the children's panel, courts and formal community care reviews.

Unison said the workers had voted by a majority of 96% to take part in a 'work-to-rule' from Monday in protest at a council pay and grading review which they claimed has downgraded their jobs and left many facing a loss of �1,000 a year.

Members have not only lost faith in the process but are now being bullied by their employer and threatened with suspension for exposing the failings of the exercise Brian Smith Unison

Brian Smith, secretary of Unison's Glasgow social work stewards, said: "The members have clearly been allocated to the wrong role profile by the council's job evaluation exercise, but despite the opportunity to address the problem at the review hearing the employer failed to take it.

"They therefore voted overwhelmingly to demonstrate what working to the role allocated would mean.

"Members have not only lost faith in the process but are now being bullied by their employer and threatened with suspension for exposing the failings of the exercise.

"The council has so far not approached the union to discuss emergency cover, and Unison is angry at council statements attempting to pin the blame for loss of service to users on these staff."

A council spokesman said the action would be unnecessary. He said: "It is clear that the unions have adopted a strategy of trying to force the council's hand by hurting the most vulnerable in society.

"It is a cruel and cynical tactic and Glaswegians would not expect us to give in to it.

"The majority of people who are threatening action have lost no money under the review and we are committed to ensuring that those who are in detriment have their incomes protected in the long term."