A car parts manufacturing plant in Llanelli is cutting 95 jobs due to a "significant drop" in its sales.
Calsonic Kansei, a Japanese firm, which employs 400 people at its plant in Llanelli, announced proposals for redundancies on Wednesday.
The Welsh Government announced in December it would invest £4.4m to create 85 jobs to allow the firm to develop and produce technology for electric vehicles.
The company said the decision is due to "pressures of market instability caused by the political and economic conditions" which "have affected our customers’ volumes".
Following the announcement of the job losses, local MP and AM Nia Griffith and Lee Waters said they have "deep concern" about the proposals and will be working with the company and trade unions to help the workers affected.
In November, automotive business Schaeffler announced it is to close its site in Llanelli completely - with the loss of 220 jobs.
The site, which makes engine parts, has been in the town for 63 years, and along with a site in Plymouth, production will be relocated to the US, China, South Korea and Germany.
A Welsh Government spokesperson said the news is "incredibly disappointing for the workers, families and the town."
It said it "reinforces" the need for the UK Government to "understand the serious instability Brexit is causing in the economy and the consequences their botched negotiations are having on jobs and investment."
The UK Government issued the following response:
“The decision for Calsonic Kansei to reduce its workforce at its Llanelli factory is a commercial one. This is a concerning time for their workers and the government stands ready to support those affected.”
In a statement, Calsonic said it will do "everything reasonably possible to reduce the impact of this proposal on its employees."