The 2500 workers at the factory, where production of the XJ saloon is soon to end, are set to vote on the proposals, which would potentially reduce any risk of further redundancies.
The plans, which would see the plant in operation from Monday to Thursday, were detailed to workers in a document titled “The Merlin Gateway Agreement”.
The briefing states: “We are proposing a new 37 hours a week, four-day shift pattern".
"For those employees working this pattern”, it continues, “the benefit will be more days away from work to spend how they choose while also reducing travel and childcare requirements.
"When working a shift pattern there may be times when we need to deliver extra volume or recover unplanned losses.”
The move is the latest in a series of disruptions for Castle Bromwich workers; last year it was reported that they would be moved to a three-day week, and recent uncertainty surrounding Britain’s departure from the EU prompted a four-day shutdown in April.
Production of the brand’s 10-year-old flagship XJ saloon will end on 5 July, with details of its successor’s arrival date and production remaining scarce.
Recent sales reports from Jaguar show that 651 XJ models were sold in May 2019, compared to 511 within the same period in 2018. This is almost certainly due to the imminent end of its production run, with sales expected to stay strong while dealer stocks last.
Autocar has previously reported that Jaguar is evaluating the potential to revive the XJ as a fully electric rival to the Porsche Taycan and Tesla Model S.