Embattled “Boris Bus” maker Wrightbus has finally collapsed into administration, taking 1,200 jobs with it and putting twice as many positions in the company's supply chain in danger.

Administrators Deloitte said just 50 staff will remain at the Northern Ireland firm to keep it ticking over in the hope of finding a buyer or salvaging some value from the Ballymena-based business.

Unions are demanding that Prime Minister Boris Johnson steps in to "do something decent" by helping rescue the company, rather than leave staff to face "devastating consequences".

Jackie Pollock, Unite regional secretary, said: "Just three months ago Boris Johnson gave assurances that he 'will do everything we can to ensure the future of that great UK company'. He has a chance today to do something decent."

The union boss added: "This is a workforce at the cutting-edge of technological advancements in the design and supply of green public transport. We cannot afford to lose any more jobs or skills in this area."

Mr Johnson - who made new double-decker buses a flagship project during his time as London mayor - will now face pressure from local DUP MPs. In July the Prime Minister said he would do everything he could to save the company from collapse.