Thousands of schools could close affecting millions of children as a result of strike action over pensions, workload and pay

One of the country's main teaching unions has voted to strike over pensions, workload and pay – a move that will exacerbate already strained relations between the government and public sector workers.

The NASUWT, which represents teachers and headteachers in most state schools in England and Wales, balloted 227,500 of its members. Some 82% voted in favour of a strike with a turnout more than 40%.

This union is the fourth teaching union to vote for industrial action. Its general secretary, Chris Keates, would not confirm whether she would be encouraging members to join two million public sector workers on 30 November when more than 20 unions could go on strike. However, she said she would "bear the date in mind". Most of the action is likely to start at the beginning of December.

The action on 30 November is expected to be the biggest day of industrial unrest since the 1979 Winter of Discontent.

The union's membership was asked to strike over what it said was an "excessive workload, rapidly worsening pay and conditions and increasing job losses" as well as reforms to teachers' pensions. Keates said her members had voted "emphatically and decisively for industrial action".

The result is likely to mean that thousands of schools will close, affecting millions of children.

Some 91% of members voted for action short of a strike, which could mean refusing to administer exams, supervise detentions or cover for absent colleagues.

It is the first national industrial action ballot the union has called in over a decade. Keates said her members' patience had been severely tested and were "embarking on a quiet revolution to put quality education first".

She said teachers had been faced with a rising tide of excessive workload and a series of attacks on their profession. These included "unjust pension reforms, worsening pay and conditions of service, and increasing job insecurity," she said.

"With such deep levels of demoralisation, our schools are on the brink of a crisis affecting recruitment and retention. Only the recession is preventing a mass exodus. They have confirmed that we cannot go on like this."

On Thursday, probation officers, bus drivers, police civilians and museum staff also backed a pensions strike. Unite said 75% of those who took part in its ballot said yes to taking part in the strike, with a 31% turnout covering over 200 employers.

Last week members of the National Association of Head Teachers voted for strike action over pension plans – the first strike vote in the union's 114-year history.

In June, the National Union of Teachers balloted its members to strike. Some 92% voted in favour of strike action, with a turnout of 40%. At the same time, the Association of Teachers and Lecturers, which is seen as the most moderate teaching union and has never taken national strike action before, balloted its members. Some 83% in favour of a strike on a 35% turnout. Both unions will carry out rolling strikes.

Teaching unions are furious that the government has proposed to raise the state pension age for teachers in England and Wales to 68 from 65 and to increase their pension contributions by half in 2014. They also object to changes to the way their pensions are calculated. Ministers want to uprate pensions and benefits according to the consumer prices index, which historically has risen by a smaller amount each year than the retail prices index.

The government argues that the changes are needed because the cost of teachers' pensions is likely to rise from about £5bn in 2005 to almost £10bn by 2015 as more staff retire and life expectancy increases.

The planned day of action on 30 November will include regional rallies but no central event akin to the March for the Alternative, in which more than a quarter of a million people took to the streets of London over spending cuts in March. Instead, there is likely to be a focus on smaller displays of dissent, including lunchtime protests at workplaces.

Nick Gibb, schools minister, said strikes damaged pupils' education, disrupted parents' lives and undermined teachers' reputations.

He said: "Reforms to public sector pensions are essential ... Everyone is living longer and the cost of that has to be fairly shared," he said. "The government has been listening carefully to teachers and heads. We've put forward an improved offer which guarantees existing pension rights; keeps inflation-proof payouts linked to salaries and protects those closest to retirement."

He said the government was in "serious negotiations" with the unions.