Ineos had ordered closure of the plant earlier this week, putting around 8,000 jobs at risk, following the staff’s refusal to accept their survival plan, which it considers vital to curb losses at the site.

The plan included a three-year pay freeze, final salary pension scheme abolition, bonus cuts, no-strike pledge, reduced shift allowance, as well as other changes to terms and conditions.

Speaking to BBC News, Unite union general secretary Len McCluskey said that the union has now decided to embrace the owner’s survival proposal ”warts and all”.

"The unions have indicated to the company that in terms of their survival plan we have put forward our positive response to that," McCluskey added.

The union had earlier termed the Swiss-based chemicals group’s decision to close Grangemouth petrochemical plant as ‘catastrophic’ and ‘tantamount to economic and industrial vandalism.’

Ineos is yet to respond to the union’s latest move.

Engaged in production of diesel and jet fuel as well as gasoline, Grangemouth is considered to be Scotland’s largest industrial site and its only refinery, as reported by Reuters.