BRITISH Airways has begun a consultation on redundancies it said are the result of passenger numbers due to a reduction in passenger numbers in the midst of the coronavirus pandemic.
BA said 399 job cuts were being considered in South Wales.
The airline said it would act to try and protect as many jobs as possible.
BA's parent company IAG has previously announced it was to cut 12,000 jobs from its 42,000 workforce.
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British Airways could cut 66 jobs at its Vale of Glamorgan maintenance base
The proposals involve the Cardiff Airport, Pontyclun and Blackwood site which employ maintenance and engineering staff. .
Vale MS Jane Hutt said: "This is devastating news from BA which will affect highly skilled BAMC workforce and their families.
“These workers are vital to the Welsh economy and to our communities.
“I will be backing and supporting them in every way I can.”
She added: “I will be meeting with Minister Ken Skates MS, Unite the Union and BAMC workforce representatives today joining with Labour colleagues across South Wales.
“BAMC is part of our highly skilled Welsh aviation sector which must be supported at every level."
South Wales Central Conservative AM, Andrew RT Davies said: "This is devastating news for the workers at the three British Airways sites in South Wales.
"I remember when the site was first developed in Rhoose and this BA maintenance facility now employees over 650 workers and is the key to production at other sites in Pontyclun and Blackwood.
"The aviation industry has taken a hammer blow due to coronavirus and hardworking people at BA in the region will be horribly hit by this news.
"These are high-skilled jobs which will not be easily replaced in our area and this reinforces the importance of getting the economy up and running once again.
"An economic tsunami is heading our way and this is only the first wave.
“We need brave leadership at Westminster and Cardiff Bay to ensure people have jobs to return to."
A British Airways spokesman said: “We are acting now to protect as many jobs possible.
“The airline industry is facing the deepest structural change in its history, as well as facing a severely weakened global economy.
“We are committed to consulting openly with our unions and our people as we prepare for a new future.”
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