Speaking to ITV News Central Labour leader Jeremy Corbyn has taken the side of teaching assistants in Derby who've gone on strike.
The protest is over a dispute with the Labour run city council who have increased their working hours but not their pay.
Caretakers, admin workers and cooks are also affected by the changes.
Mr Corbyn said he hoped the council and UNISON can come to an agreement soon so that staff can continue doing that job without disruption.
Teaching assistants worked fewer hours a week than other staff and the council says it has a legal obligation to increase their hours.
But the union which represents them disagrees, saying on average they would end up £450 a month worse off by having their hours but not their pay increased.
The Labour leader went on to praise teaching assistants saying their role in the classroom was "absolutely crucial".
The striking staff have been staging regular walkouts, from one-hour lunch stops to full days of action, since June last year.
Earlier this week protestors created a 'human chain' around the Council House building.
Next week they've got two more strike days planned unless a deal can be agreed.
When asked whose side are you on? Mr Corbyn replied "the teaching assistants, the pupils and the parents".
In a statement Derby City Council said: