Union accuses Ineos of 'putting a gun to the heads of its workers'

Britain's biggest union has accused the billionaire owner of Grangemouth of using "menacing" tactics and "cynical blackmail" as Scotland's largest oil refinery remains shut despite workers withdrawing their strike threat.

The Unite union said it is considering legal action against Ineos, the operator of the Grangemouth oil refinery and petrochemical plant, which is jointly owned by the billionaire industrial tycoon Jim Ratcliffe.

A dispute over worker conditions had led Unite to call a 48-hour strike, due to begin on Sunday, and Ineos responded by starting a shutdown at the plant. Unite then called off the action, but as it refused to offer a no-strike guarantee in talks at the conciliation service Acas, Ineos declared that the refinery will remain shut until at least Tuesday.

Unite said it was looking to take legal action "over Ineos's 'sign or be sacked' ultimatum to slash jobs, pay and pensions". The union claimed that Ineos told workers they could lose their jobs and then be re-employed on poorer terms unless they agree to give up their final-salary pension and accept pay freezes and pay cuts by a deadline of 6pm on Monday.

Pat Rafferty, Unite's Scottish secretary, said: "This is cynical blackmail from a company that is putting a gun to the heads of its loyal workforce. We are considering taking legal action over the company's menacing tactics and urge members not to be threatened into signing their livelihoods away. We will not allow such an important national asset to be held to ransom and urge Ineos to... engage meaningfully with the workforce over a transitional agreement."

Ineos claimed it had offered staff "a top-quality money-purchase pension scheme to replace the unaffordable final salary scheme", as well as other payments. Calum MacLean, chief executive of Ineos Refining, said: "This is D Day for Grangemouth. The site is safely closed whilst we consult the workforce. If we can get the changes we want, the company has committed to investing a further £300m in the site, which will help secure its long term survival". Ineos has warned that Grangemouth is losing £10m a month and will close in 2017 without investment and cost-cutting.