A medical manufacturing plant in West Lothian is to close, with 400 jobs at risk.

Workers were told the Ethicon facility at Kirkton in Livingston, which is part of the Johnson & Johnson group, will close within 18 months.

The pharmaceutical giant's medical division announced in January that it was aiming to cut its workforce by between 4% and 6% worldwide.

Union representatives said news of the plant's closure was "shocking", adding Ethicon had received public money to support its operations.

Unite says it will do everything it can to support workers in the area.

A statement from Johnson and Johnson said: "This could potentially impact approximately 400 employees, pending the outcome of the consultation process.

"We have put forth these proposals in the interest of reducing complexity and increasing agility to better serve the needs of customers and patients in today's evolving healthcare marketplace."

The statement added: "We carefully assessed our options and recognise our proposed plans have the potential to significantly affect our employees, their families and the local community.

"We are committed to supporting them through the consultation process.

"The company is working in close cooperation with regional and local works councils and unions regarding the proposed actions."

Unite regional officer Derek Ormston said: "This is shocking news. Many of our members at Ethicon have given long years of service to the company and to be rewarded in this way will be heartbreaking.

"There will also be feelings of uncertainty and anger. Unite will now consult with our members and work hard to defend their jobs throughout this consultation process.

"We will also be looking for support from politicians and public bodies."

He continued: "Ethicon has received public money to support its operations in Livingston so they have a special responsibility to the workers.

"Following the closure of Motorola and NEC, this is another major blow to the economy of West Lothian. We can't go on like this.

"We need to start asking questions about what kind of economy we want in Scotland and how we can create an industrial strategy that will grow and support manufacturing for the years to come."

Secretary of state for Scotland David Mundell said the UK Government was involved in talks which aimed to save as many jobs as possible.

He said: "This is a difficult and uncertain time for the workers, families and community in Livingston.

"The UK Government has been working closely with Johnson & Johnson and the Scottish Government to find a solution that will protect as many jobs as possible.

"Ministers will continue to hold discussions to help secure the future of the site."

The Scottish Government's Economy secretary Keith Brown said enterprise agencies had been involved in the talks.

He said: "That work has been detailed and intensive, looking at what we can do both to help address immediate business challenges and to maximise the site's future potential.

"Unfortunately, despite our very best efforts, the company has decided to enter into consultation on possible site closure, which is hugely disappointing."

He added: "Our focus now is on working with Johnson and Johnson to try to find a new owner for the site and on doing all we can to support the affected staff through this difficult period."