The Unison union said the vital workers would be on strike on Monday and Tuesday of this week.
They are also set to launch a two-day strike starting on Wednesday 24 March.
Trust bosses have insisted that porters sign new contracts that ripped up their previous shift working patterns—or face the sack.
They expected that the workers’ union would then quickly end the dispute.
But workers’ resistance has pushed union leaders to offer support.
Unison general secretary Christina McAnea gave her wholehearted backing to the strikers and pledged the support of the whole union. Unison has also used its influence in the Labour Party to bring many local MPs on board too.
This will add to the pressure on trust leaders —especially its chair, former Labour home secretary Jacqui Smith.
The dispute at Heartlands is among many where managers are attempting to use the pandemic as an excuse to wage war on terms and conditions.
To stop the spread of “fire and rehire” practices, it is vital that striking porters keep up the pressure.