The official announcement - which was obtained by the ECHO - was circulated to JLR Halewood's 4,000 employees, and around 500 agency staff, today.
The 339-word "Notice of Change to Production" sets out the reasons for the major change to shift patterns, which the company states will affect around 10% of the workforce.
The job losses comprise a mixture of permanent employees and agency staff. The loss of the permanent employees will be through an enhanced voluntary redundancy scheme, with the shift changes coming into effect after the Easter shutdown.
The Unite union described the move as a "fresh blow to the car industry."
Responding to the news, Unite national officer Des Quinn said: “This is a further blow to the UK car industry in general and to our members at Halewood in particular.
“Unite will be ensuring that the commitment to limit job losses to voluntary redundancies is fully honoured.
“The challenges being faced at JLR are also being experienced by other UK car factories.
“The UK’s car industry has plummeted from being the jewel in the crown of the UK’s manufacturing sector in a few short years, directly as a result of government inaction.
“Until the government ensures that there is long-term frictionless trade and no tariffs with the European Union along with meaningful investment in the infrastructure to ensure the success of electric vehicles, the UK’s car industry will continue to experience severe challenges.”
The JLR message to workers in full reads:
"As part of its ongoing transformation programme Jaguar Land Rover is taking action to optimise performance, enable sustainable growth and safeguard long-term success of our business.
"Central to the Halewood manufacturing strategy, as we discussed as a team at the Town Hall last year, we can confirm we are moving from a three shift to two-plus shift pattern from Monday 20th April, 2020.
"This will deliver significant operating efficiencies at the plant, while enabling us to meet the growing customer demand for our new Range Rover Evoque and Land Rover Discovery Sport.
"BIW, Paint, Trim and Final Assembly and related production areas will move to two-plus shift working after Easter shutdown 2020.
"The two-plus shift pattern was agreed as part of the last pay negotiations and will allow us to respond to customer demand with fewer line rate changes which are disruptive to both our people and the plant.
"It is expected that maintenance teams will move to a three shift from a four shift pattern. For clarity T&PPG will remain on three shifts.
"This change in shift pattern affects about 10% of Halewood's workforce.
"Jaguar Land Rover employees have the opportunity to leave through an enhanced voluntary redundancy programme and we expect to also reduce some of our agency workforce within that 10%.
"The VR programme will allow long-serving permanent employees to be released from the business to retire with dignity with an enhanced separation package.
"If the company receives the required level of interest in the voluntary redundancy programme, we anticipate there will be opportunities to retain our longer serving, high performing and committed agency colleagues.
"The voluntary redundancy programme will open for applications in early February. A summary of the terms and application process is below.
"Technology teams and support departments will continue to work on the facility and people plans required to deliver a smooth transition to this new working pattern and will ensure your Trade Union representatives are briefed. We will update you on our progress and thank you for your patience and understanding."