Workers are set to strike at Mahle Engine Systems in Kilmarnock after failed eleventh hour negotiations over the manufacturing plant's future.
The industrial dispute follows the potential loss of 260 jobs at the site.
Mahle manufacturers automotive engine systems and components including piston systems, cylinder components and valve train.
The strike was the consequence of "stonewalling" by Mahle bosses over the future of the plant, Unite claimed.
Mahle chiefs aims to relocate manufacturing work to sites in Slovakia and Italy, the union said.
Unite regional industrial officer, Jim White said: "We asked for assurances that the plant could tender in a fair and time-bound manner for new work – this was road-blocked. We asked for decent redundancy payments for workers employed on contracts that Mahle refused to negotiate on – this was refused."
Mahle directors had not given the Kilmarnock site "a fair chance" White added.
Workers will launch a 24 hour strike today (Tuesday 24 April) with two more walkouts scheduled on Thursday and Saturday.