The Unite Union will today start consultations with electronics giants Sharp after the firm's announcement it'll stop making solar panels at its factory in Wrexham.
Bosses have blamed "unavoidable market conditions" for their decision.
Two hundred and fifty posts will be shed. It also won't renew around 350 agency workers' contracts.
Microwave ovens will still be made there.
More top news
Showers this evening with heavier and more persistent rain arriving overnight. A wet start tomorrow but improving during the afternoon.
A mother from Neath has told how her teenage son collapsed and was left unconscious for five hours after taking a so-called legal high.
Two brothers from Cardiff are campaigning for their cousin's murder to be re-investigated, 76 years after she died.