Global pharmaceutical giant Pfizer is to shed up to 240 science jobs at its Kent plant.

The company is axing between five and eight per cent of its research and development workforce worldwide, which could affect at least 150 people and possibly many more in Sandwich.

The move follows Pfizer’s decision to focus its research in six disease areas: Alzheimer’s Disease, cancer, schizophrenia, pain, inflammation and diabetes.

The company says these are the areas with the highest probability of success, address an unmet medical need and have high market growth potential.

It is dropping cardiovascular disease, where Pfizer has been a dominant player with Lipitor, the world’s top-selling drug. Lipitor faces competition from 2011 with Pfizer anticipating a steep drop in revenue.

A spokeswoman said: "Because we’ve restructured our research effort, it’s obviously going to have an impact on people working in other areas and we have to align our employees better with our new research efforts.

"So, over the next several months we will be looking to reduce our research staff by between five and eight per cent globally."

There is uncertainty over the precise number of people who will lose their jobs at the Kent plant. Up to 3,500 people work at Sandwich but not all are employed on research and not all directly employed by Pfizer.

If the job cuts are made to the lower figure of 3,000, five per cent would involve 150 people losing their jobs. But eight per cent would make it 240.

A 90-day consultation with affected staff got under way on Tuesday. The spokeswoman said the company would do all it could to mitigate job losses, with some people being offered vacancies elsewhere in the company.

"We are not able to give out any specific figures for Sandwich but we’re using the five to eight per cent figure here as well," she added.

In a statement, Pfizer said: "We are aware this decision will affect a number of people – colleagues, their families and the community.

"We are committed to supporting our colleagues through this transition. Pfizer does not make these decisions lightly. Everyone affected will be treated with utmost respect and will be offered appropriate financial, professional and personal support.

"It’s important to point out this is an ongoing evolution of Pfizer Global Research and Development and Pfizer as a whole. We continually look for ways to operate our business more effectively and efficiently to create value for all of our constituents."

Pfizer’s workforce at Sandwich - where the company has been established since the 1950s - has reduced considerably in recent years.

Multi-million pound investments in the plant, which played a key role in the invention of impotence drug Viagra, led to a rise in staff numbers to around 5,000.

But some office staff were switched to Surrey and gradual job cuts over the past few years have reduced the workforce to its present levels.