BMW plans to axe about 18 per cent of its agency workforce at the Cowley Mini plant, it emerged last night.

About 140 temporary workers are thought to be at risk after car sales dropped in August, but the exact figure had not been confirmed last night.

The company will be halting Saturday morning production later this year after it admitted “a good deal of uncertainty” was affecting the motor industry.

A change in shift patterns, planned for November, will be introduced after the company reported sales in August were down 6.7 per cent on the previous year.

The workforce will be briefed today and two options will be put to a ballot.

The news comes despite plans to roll out a string of new models, including the Mini Coupe, and expand the Oxford factory.

The firm confirmed last night its full-time employees would not be affected by the job cuts.

About 4,000 people work at Cowley, with 800 employed on a temporary basis.

Group communications manager Angela Stangroom said: “While the company remains cautiously confident about the strength of the global automotive market, a good deal of uncertainty persists and it is vital production patterns are able to respond flexibly to the fluctuations in demand.”

The firm said most of the at-risk workers had been taken on during the summer on short-term contracts to provide holiday cover.

It stressed last night it would give workers – who are employed by agency right4staff – five weeks’ notice.

Dr Jurgen Hedrich, managing director at Mini Plant Oxford, said: “It is always regrettable when we are not able to extend the contracts of temporary workers.

“We are working closely with right4staff who will aim to place affected workers elsewhere, including at our other UK operations.”

Hundreds of agency staff were affected by lay-offs at the plant in February last year.

One agency worker, who wished to remain anonymous, said last night the mood was once again glum at the factory.

He said: “Only recently they have been sending text messages to people asking if they know of anyone who needs any work.

“I know of one person who gave up their job to come here one week, now the next week it looks like they will be completely out of work.

“There have been quite a few new faces joining recently so I think people thought it was looking up. But they will probably be the first to go.

“I hope I will be all right this time but there is just no guarantee. It’s just not good news for anyone.”

Gawain Little, president of the Oxford and District Trades Union Council, said he could not comment on the shift cuts.

But he added: “One of my biggest concerns is that this is exactly the sort if thing we’re going to see more and more of.

“And as the public sector cuts start to bite, the knock-on they will have on the private sector, and the local economy, is scary. It’s quite a frightening time.”