The public sector pensions dispute worsened today when a row broke out over the cost of next week's strike and a union leader warned that industrial action will continue into 2012.
Government ministers said the 24-hour walkout on November 30 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 bitter 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 it was difficult to predict the impact of the strike, but the cost to the economy was based on the expectation that two-thirds of schools will close.
"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."
The Prime Minister said the Government would do all it could to ensure the country keeps running next week, but he warned there would be disruption due to the "irresponsible" actions of trade union leaders.
Speaking during a visit to Toyota in Burnaston, Derbyshire, David Cameron said: "The offer we have made is a generous offer. The factory I'm standing in here in Derbyshire, Toyota, the employees working behind me here, they don't have access to anything like the pensions that people get in the public sector and they are paying taxes towards those pensions and they are going to suffer."
TUC leader Brendan Barber said: "Blaming the weather, the royal wedding and now scapegoating hard-working teachers, nurses and dinner ladies for the UK's economic woes is pretty poor from a Government that has presided over record unemployment and the weakest economic recovery for a century."
GMB leader Paul Kenny said it was "inevitable" there will be further national strikes in the new year as well as targeted industrial action in December, adding that the Government would be making a mistake if it believed workers would "pack up and go home" after the walkout next week.
He also revealed that unions had established a fund of "tens of millions of pounds" to pay the wages of some public sector workers who go on strike so that action can be maintained.
Unions also criticised moves to draft in civil servants from across Whitehall to staff facilities at ports and airports to cover for immigration officials.
Mark Serwotka, leader of the Public and Commercial Services union, said: "Our members take two to three months to train - the idea that people can cover after a few days' training is absurd."
Labour leader Ed Miliband urged the Government and unions to leave "no stone unturned" in looking for a compromise.
"I am very concerned about the cost of these strikes and that is why both sides must work to stop these strikes happening," he said.