Government ministers said the 24-hour walkout on 30 November by more than two million workers will lower output in the public and private sectors and could cost the economy half a billion pounds and lead to job losses.
Cabinet Office minister Francis Maude said there was a correlation between economic output and employment, adding: “Exactly what that relationship is is very hard to anticipate but if we lose a big chunk of output it is hard to see how that does not translate into fewer jobs.”
Unions accused the government of “fantasy economics” and of “plucking figures out of the air” as they finalised plans for rallies, marches and meetings in towns and cities across the country next Wednesday, in the biggest outbreak of industrial unrest since the 1979 Winter of Discontent.
The CBI said disruption will cost hundreds of millions of pounds at a time when everyone should be “working to help the recovery”.
Ministers said the biggest impact will be caused by thousands of school closures, forcing parents to work from home, make childcare arrangements or take their children to the office.
Chief Secretary to the Treasury Danny Alexander said there was “no more money on the table” to settle the row over the government’s controversial pension reforms – adding that he may take his daughter to work on the strike day as her school will be closed.
Mr Maude said the estimate of the cost to the economy was based on the expectation that two-thirds of schools will close for the day.
“There will be a massive impact on schools, which has the biggest knock-on effect on the economy. We are confident that emergency care in the NHS will be maintained, but there will be people whose operations are delayed. That is a very great tragedy.”