Bus builder Alexander Dennis is planning to cut a a further 70 jobs at its Falkirk base, according to trade union Unite.
This latest jobs cut would be in addition to the 200 jobs previously announced as at risk.
This would mean a loss of almost a third of the 850 employees on the site.
The trade union, which represents the majority of the company’s workforce has also severely criticised Scottish Secretary Alistair Jack MP for the lack of any response to a letter dated 10 September from Unite
It had invited him to meet with workplace representatives to discuss the current situation facing Alexander Dennis in Scotland, and what levels of support could be provided for the low-emissions bus industry.
In a normal year about 25% of ADL’s order book are made up of orders from within Scotland and much of the rest is from the UK.
The union has called on the UK Government to bring forward the promised funding for 4,000 low-emission buses through a £3bn fund.
It has urged the Scottish Government to act on the Just Transition Committee’s recommendation to rapidly roll-out spending of the £500m committed to prioritise buses.
It has also called for a Scottish-wide bus scrappage scheme to replace older diesel buses with low emission and zero-emission buses.
In particular it has urged the immediate procurement of a fleet of green buses for use at COP26 in Glasgow next November.
It also urged the acceleration of orders to bus manufacturers and the supply chain through the new Scottish Ultra-Low Emission Bus Scheme, which will provide £9m this year to help bus operators invest in ultra-low emission vehicles.
Unite Scottish secretary, Pat Rafferty, said: “The prospect of Alexander Dennis further cutting its workforce by 70 jobs in addition to the 200 announced a number of weeks ago is staggering.
“Unite has worked day in and day out to ensure the company honours the agreed consultation processes with the workforce.
“The sole objective for all should be to maximise the efforts to save jobs and to financially support workers through redundancy.”