A union calls the plans "ill-thought out", but management says change is needed due to rising costs.
A union says the announcement came as a blow to employees with up to 275 positions at risk.
A "financial risk" fund has been put aside by Coventry City Council as an equal pay row rumbles on.
GMB Union says workers at Briggs Marine in Immingham will go on strike from 9 March.
Workers at Barnsley Hospital will be balloted in a row over contract changes, the GMB union says.
The company says plans to outsource delivery to DHL will impact staff at three depots.
As staff continue to be tested as a precaution, Amazon says, a union calls for the site's closure.
Union bosses have commissioned a report which includes a number of recommendations.
Refuse, street scene, and grounds maintenance workers were due to launch several walkouts.
