'BETRAYED' workers at Oxford's Mini plant have threatened to walk out over pension changes that could leave them thousands of pounds out of pocket.

Union bosses at Unite said they had tried negotiating with plant owner BMW but the carmaker was 'ploughing ahead' regardless.

A spokesman confirmed the union was now preparing to ballot members for strike action that could take place in the coming months.

It comes after warnings that proposals to end the final salary pension scheme for about 2,000 people could leave some workers losing six-figure sums.

BMW argues the change is necessary to address a pension scheme deficit.

But Tony Murphy, Unite's national officer for the automotive industries, said: "BMW’s UK workforce has worked hard to help deliver record profits in excess of £5 billion for the carmaker.

"They feel betrayed by its decision to close their final salary pension scheme, which will rob them of the future retirement they have worked hard for.

"Unite has tried to negotiate with the company in good faith and put forward proposals to keep the pension scheme open.

"To our bitter disappointment the carmaker has not returned that good faith and is instead ploughing ahead.

"Unite is now making arrangements to hold a full statutory industrial action ballot which, given the strength of feeling, could result in industrial action in the coming months.

"We would urge BMW bosses to recognise this by negotiating meaningfully over keeping the pension scheme open and honouring their pensions promises."

A consultation on the pension changes is currently taking place and ends next Tuesday.

The proposals would see the current ‘final salary’ pension scheme end, with workers instead moved to a ‘defined contribution’ scheme.

This would mean the maximum pension an employee could receive would fall from 40 per cent of their wage to 26 per cent.

In a letter to union members, Mr Murphy said Unite had asked BMW to provide its response to the consultation but bosses claimed to have not made a decision and instead suggested another meeting in February.

He wrote: "We expressed our bitter disappointment at this and told the company we now think they are just playing us along, wasting time and informed them we will now commence the process of industrial action by engaging with the Electoral Reform Society for a postal ballot ASAP."

One plant worker, who spoke on condition of anonymity yesterday, said: "It's a very controversial change because when BMW took over the plant it said the pension scheme under Rover would carry on.

"They are the best pensions to have and these changes would mean a massive decrease in the amount of money people will get.

"This is not like the BHS pensions scheme where there was a loss in funds.

"BMW is making millions and millions but all of a sudden they want to stop this pension scheme – it just seems so unfair."

Labour's Andrew Smith, MP for Oxford East, yesterday called on both sides to settle the differences around the negotiating table.

He said: "Keeping a good quality pension scheme is understandably a key priority for the workforce and their families.

"I very much hope this can be secured through negotiation as BMW and Unite have successfully done many times on many issues."

A BMW Group spokesman said: "The company is aware of Unite’s decision to hold a ballot for industrial action, however it is still consulting with its employee representatives regarding the proposal to close its two UK defined benefit pension schemes to future accrual and no decisions have yet been made."