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.
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Showers expected throughout the day especially in the north. Drier and brighter elsewhere but cooler than in recent days.
Most places will become dry overnight, although it will remain generally cloudy with patches of hill fog.
Police have told people in Pontypridd that the cordon around the rugby club could be in place until next week.