Car giant Nissan is to end the night shift at its UK plant, workers have been told.
Unite said it believed no jobs will be lost at the plant in Sunderland as a result of the decision, but workers will lose a shift allowance.
The move follows a decline in car sales and has raised fears of a knock-on effect in firms that supply Nissan with parts.
The plant employs about 3,000 workers on the night shift.
Unite assistant general secretary Steve Turner said: “Unite has been aware of this announcement for some time and our officers and reps at the plant have been working hard to ensure that the full workforce is protected.
“As a result, no jobs will be lost with current demand being consolidated into the remaining day shifts.
“Protecting jobs and the families and communities that rely on them is what strong unions do, and Unite has done that again here in very difficult circumstances.”
Nissan said last week that plans to build the Qashqai in Sunderland had not changed following speculation it could change its mind if the UK leaves the EU without a deal.
The company said that, along with other firms with major investments in the UK, it was waiting for clarity on what the future trading relationship between the UK and the EU will look like.
The car industry has been warning for years about the impact on the sector of a no-deal Brexit.
The Sunderland plant makes the Qashqai, Juke and electric Leaf models.
Car sales in September, the industry’s second most important month, increased by 1.3% from a year earlier, well below the double-digit growth hoped for.
In the first nine months of the year, car sales fell 2.5% to 1.86 million, the Society of Motor Manufacturers and Traders (SMMT) reported earlier this week.
SMMT chief executive Mike Hawes said September’s rise was “fairly paltry.”
He added that consumer confidence was being undermined by political and economic uncertainty.