Wylfa on Anglesey has beenchosen as the preferred site for a large-scale nuclear power plant.
Andy Prendergast, GMB National Secretary, said:
"The go ahead for Wylfa is much needed and overdue contribution to the nuclear baseload.
"Without new nuclear, there can be no net zero.
"The project will also provide badly needed jobs and reinvigorate a community.
"All political parties must now support this decision and make sure there are no delays and progress is made as soon as possible."