Hundreds of furloughed workers at the Ford engine plant in Bridgend have returned to work on Monday.
More than 1,000 employees in Bridgend have been on furlough since March because of the coronavirus pandemic.
A limited number of employees had continued to work on company sites in the UK over recent weeks to ensure the ongoing provision of critical services.
Ford outlined a series of health and safety measures which will be put in place, including requiring anyone entering a Ford facility to use a company-provided face mask, and a face shield in select manufacturing positions and other positions where social distancing cannot be met.
Everyone entering a Ford facility will have their body temperature checked with scanning equipment, and a daily, wellness self-assessment of workers will be made.
Work areas have been redesigned to ensure social-distancing guidelines are maintained and there will be a phased return to work to reduce employee density in buildings and on production lines.
Ford confirmed last year that it plans to close the plant in Bridgend in September.
Work has also resumed at Ford's engine plant in Dagenham, Essex.
"As we return to work at our two engine plants in the UK, our key priority is the implementation of Ford's global standards on social distancing and strengthened health and safety protocols to safeguard the well-being of our workforce," said Graham Hoare, chairman of Ford of Britain.
Aston Martin has started a phased return to work for a number of its manufacturing staff at its manufacturing facility in St Athan.