The strike has been planned for this Friday after union bosses said Sandwell Leisure Trust workers such as swimming instructors, lifeguards and receptionists were told if they did not accept the new agreements, which will affect pay, their jobs could be at risk.
The trust runs nine centres across the borough, including Smethwick Baths, Langley Swimming Centre and Haden Hill Leisure Centre.
Unison said it condemned the use of “fire and rehire” tactics which force staff to accept unfavourable new terms, including no longer being paid nationally agreed rates.
Staff represented by the union voted to take strike action. The leisure trust runs centres and facilities on behalf of Sandwell Council.
Workers last went on strike on April 30.
Unison West Midlands regional secretary Ravi Subramanian said: “Sandwell Leisure Trust must do the right thing and restore employee’s terms and conditions, including pay, in-line with national agreements."
UNISON branch secretary for Sandwell Tony Barnsley said: “At a time when a £73m is being ploughed into the new aquatic centre being built in the borough, there can be no justification for workers’ terms and conditions to be cut.
“Staff running Sandwell’s leisure centres during these difficult times shouldn’t be subjected to such treatment when the trust has £3.9m in the bank.”
Sandwell’s Labour MP John Spellar, who supported the first strike day on April 30, said: “Even Boris Johnson has called fire and rehire tactics unacceptable, although he hasn’t done anything about it. So, everyone in Sandwell must be concerned at moves to do this at Sandwell Leisure Trust.
“We need to support the employees taking action to defend national agreements and terms and conditions. Sandwell Council need to intervene before this situation worsens.”
A spokesman for Sandwell Leisure Trust said those agreeing to strike represent 16 per cent of the total workforce.
The spokesman added: "The pandemic has had a significant impact on the leisure industry and the recovery from this will take some time and is uncertain. As many businesses have needed to do, the trust has taken prudent measures to manage increased costs with fixed pay awards for two years, while no other changes to terms and conditions have been made.
"Only one trade union actually received a mandate to strike by their members and those agreeing to strike only represent 16 per cent of the total workforce, plus only seven per cent of these actually took part in the last strike day.
"New contracts have been issued and accepted by all staff and SLT is committed to protecting the jobs of its workforce both now and in the future by managing its increased costs to ensure its ongoing sustainability."