Six hundred bus drivers in Kent are to go on strike in disputes over pay on September 30.
The union's general secretary Sharon Graham said: "Our members at Arriva have generated huge profits for the company for decades.
"Arriva can afford to offer a pay increase that meets the real rate of inflation but it has put profits before people and declined to do so.
"Unite will leave no stone unturned in the support given to our members during this dispute."
Unite regional officer Janet Nobbs previously said: “Bus strikes will inevitably cause severe disruption across Kent but this dispute is entirely of Arriva’s own making. Arriva has had every opportunity to resolve this dispute but it has chosen not to do so.”
The workers have already turned down a pay increase offer of around 10%, with the union describing the offer as 'a real terms pay cut' as it doesn't match 'the real rate of inflation' which stands at 12.3%.
The union’s Arriva members in Buckinghamshire have also recently announced strike action beginning this month, while the planned action by drivers in Essex has been called off after workers accepted an improved pay offer.
A spokesperson for Arriva previously said they will continue to keep their customers and stakeholders updated, and they apologise for the inconvenience this will cause across the region, particularly as our schools return for a new academic year.