About 850 more workers are expected to be axed from their jobs making the Mini car at BMW’s Cowley plant tomorrow.

Workers finishing their shifts early tomorrow morning ahead of a week-long shutdown of the plant were expected to be told of the widespread redundancies.

Tonight BMW refused to confirm numbers but it is understood the job losses are likely to be about 850 with the majority being among workers hired through employment agencies.

Weekend production is expected to end completely, with all permanent weekend workers moving to a revised five-day working week.

The company has been hit by a slump in sales.

Worldwide sales of the Mini in January were 34.5 per cent down on the same month last year, while the plant's 4,500 workers were ordered to down tools for nearly a month over Christmas, because of the worsening economic slump.

Similar shutdowns are taking place this week and later in the year.

When asked whether jobs would be lost, Cowley union convenor Bernard Moss said: “Yes. I think the number would be significant (but) I am not at liberty to say how many yet.”

The move follows lay-offs of agency workers at the end of last year.

The total number of agency staff already laid off by BMW stands at 430. The company originally announced it was letting 290 go by Christmas — a figure later revised to 380.

Unions and managers have been negotiating new shift patterns as a way of staving off mass redundancies.

Mr Moss said: “We have agreed a shift. They (workers) knew when I spoke to them that to do that it could only mean volume less than we’re currently producing and it will have an effect on jobs.

“It’s not new. I have seen it before several times. The big one was in 1992, when they nearly closed the plant.”

A BMW spokesman said putting a figure on the number of job losses would be “speculative” but that talks over changes in working practices were continuing.

She added: “We haven’t confirmed any numbers and we haven’t confirmed what the shift pattern changes are going to be.”

Oxford East MP Andrew Smith said: “If this is correct, then this is very bad news.

“Every job that is lost is a tragedy for the workers affected and their families and has a knock-on effect in the wider community.

“It’s no consolation for those affected, but Mini and the Cowley plant remains in a stronger position that most other car plants.”