The company has refused to comment on reports that a minimum of 90 posts are likely to go at its Cross Gates factory which, together with its predecessor Charles H Roe, shares a long and proud history in Leeds.

A letter sent to employees, seen by the YEP, confirms that those seeking voluntary redundancy should notify the group's HR manager, Brian Barker, in writing by 1pm on Wednesday, August 27, "when it is proposed to close the list for potential volunteers".

Optare, in Manston Lane, was formed in 1985 by workers from the former Charles H Roe company which was closed by British Leyland a year before. Roe had been at the site since 1923.

The firm's recent history has been turbulent.

It was sold for the second time this year, in June, when Darwen Holdings plc of Blackburn agreed to acquire its holding company, Jamesstan Investments Ltd, in a £15.95m deal.

Jamesstan, controlled by North East businessman Roy Stanley, had bought Optare in March and had made managing director Bob Coombes redundant in May.

A planning application was submitted – and rejected – earlier this year to build housing on the Cross Gates site with the firm's then owners suggesting they would relocate to a new, unspecified location in West Yorkshire.

The new owners announced the proposed redundancies on Friday, July 25, and the process is ongoing despite the firm winning a series of multi-million pound contracts.

It recently received a £2.3m order from London United for 19 midi buses to add to a £14.25m, 94 bus deal with two subsidiaries of transport operator the Go-Ahead Group.

When asked whether the new business wins would have any positive effect on job numbers in Leeds, a spokesman for Optare said: "Optare is currently undergoing a consultation process reviewing the business and I have no new information to offer."

The company has been holding a series of what it describes as "coffee and doughnut" sessions with staff and union representatives.

The next collective consultation meeting is scheduled to be held during the week commencing September 1.

The letter to employees is signed by the firm's chief executive officer, Andrew Brian, who concludes: "I thank you for your co-operation and support at a time which is particularly difficult for those working for the company."

Optare employs 550 staff and has a turnover of £60m.