'This is the summer of our discontent': The ATL is preparing to strike for the first time in 30 years

To those involved in the education world, Easter conjures up images of teachers' unions threatening strike action over this, that and the other. Larger class sizes? We'll refuse to teach them. A pay freeze? We'll ballot on industrial action up to and including strike action. Always, with almost every motion, "up to and including strike action".

The discerning reader, though, will remember that most of these stories emanate from the National Union of Teachers' (NUT) conference. Definitely not from the Association of Teachers and Lecturers (ATL) – described as the "traditionally moderate" union in the lexicon of education correspondents.

This Easter, though, tells a different story. The ATL, whose strength in years gone by was in the selective grammar schools, is girding its loins. Its action committee, which has not met for 10 years, has had to be dusted down. It will debate a call for industrial action over the threat to teachers' pensions at its conference in Liverpool next Tuesday. If passed and agreed by members in a ballot, strike action could take place as early as June. It will be the first time the union has taken national industrial action since 1979 – when its members quietly withdrew from their classrooms to their staff rooms to discuss a pay claim.

Pensions may be the issue most likely to trigger industrial action, but Mary Bousted, general secretary of ATL, detects quite a different mood amongst members this year than last.

"I think teachers are a bit shell-shocked at the moment," she told The Independent. "It is very tough in schools and local authorities just now."

In her speech to the conference next week, she will highlight the cuts that are being made to education spending despite the Government's promise to ring-fence spending on school budgets.

Central services such as speech therapy, help with adolescent mental health problems and education psychologists are all but disappearing in some areas.

"All these professionals' services are needed most by the most disadvantaged pupils," Bousted says.

Individual schools are also facing the prospect of making teachers redundant – particularly at sixth-form level in schools where the Government is wielding the spending axe to put them on an equal footing with colleges, which have traditionally had less money spent on them.

The conference theme is: "The Disappearance of State Education" – a provocative title, hardly designed to curry any favours in the corridors of Whitehall. Yet Bousted justifies this by saying there has been a shift of emphasis in state provision. "It is the difference between a state education service and a state-funded education service," she says. "In the past we have had a state education service, where the state has said we will employ teachers and we will employ staff and the pupils will be taught a broad and balanced curriculum. The school will be part of the local authority. Services which impinge directly on the well-being of the child – such as speech and language therapists – will be provided.

"Now the state will just provide the money and say 'get on with it'. It doesn't need to be broad and balanced.

"Indeed, some of the free schools specifically won't provide that – take Toby Young's school in west London, which has a classical curriculum and where pupils won't be taught IT."

Under the new regime, it would be up to parents to shop around in a market place to find what they want. Dr Bousted says she can judge the mood of the members by looking at the motions they have tabled for conference. In the past, the ATL has justifiably declared itself "the education union", debating issues such as the impact of poverty on the classroom, the misuse of mobile phones in the classroom and a host of other social issues. This year, she says, they are mostly concerned with the "bread and butter" issues of teachers' pay, pensions and conditions.

A similar transformation has taken over the agenda of the National Association of Schoolmasters Union of Women Teachers (NASUWT). Its agenda is usually dominated heavily by the issue of pupil indiscipline. In the 1980s, it was the last of the teachers' unions to vote against the use of corporal punishment and has always fashioned itself as the union most concerned to promote discipline in the classroom. It was the NASUWT whose members staged strike action at the Ridings School in Calderdale in the mid-1990s in order to secure the exclusion of about 60 troublemaking students from the school. Its actions, it always argued, were designed to create orderly classrooms for the majority of pupils who wanted to work – "industrial action with a halo", as its then general secretary Nigel de Gruchy declared.

This year, though, discipline does not even make it into the top six issues that are guaranteed the opportunity of a debate at its conference in Glasgow.

What issues do? You've guessed it: funding cuts, the growth in academies and free schools, and pensions.

The ATL, of course, will not be alone in demanding industrial action over the Easter weekend to combat the problems the education world.

The NUT will be demanding support for "discontinuous" strike action over the pensions threat – ie, a series of one-day strikes in a bid to persuade ministers to change their minds.

Kevin Courtney, the union's deputy general secretary, explains the threat as follows: the increase in pension contributions will cost the average teacher around £100 a month. Given that most will probably still retire at 60 despite the retirement age being eventually raised to 68, they could also be losing out on their pension payments to the tune of another £100 a month. Teaching, he argued, was too exhausting a job to carry on at until 68.

The NUT's greater militancy can be detected in its motion on the public spending cuts, where it seeks to mount a campaign to defend every job under threat. "There is no need for any cutbacks or job losses anywhere in public services," it vows. "In fact, there should be increased investment in public services if we are to get out of this crisis. After World War II the UK was in much more debt and yet this did not stop the creation of the welfare state, the NHS, pension rights and many of the services we take for granted in a civilised society." It calls on the union to adopt the approach of "not a single job lost in public services".

The NASUWT is taking a softer line on pensions – arguing that it is premature to resort to industrial action while negotiations between the TUC and the Government on pensions continue. That should not be construed, though, as evidence that it has any better a relationship with the Government. If anything, the reverse is true. Its general secretary, Chris Keates, has been one of the most critical voices raised against coalition education policies.

"I regard it as my responsibility to try and deal with any government, whatever their political colour," she says, "but normally there is something you can find in a general response to what they're doing that is good but – with their free market approach – it is very, very difficult."

So what will the upshot of all this be? Well, expect strike action over pensions to hit schools in the summer term. Even the headteachers' unions, usually more loathe than the ATL to countenance industrial action, have said their members would favour it.

Expect, too, more sporadic action over the impact of education cuts if teachers face redundancies in the summer term.

Will it have any impact on the Government? Not over the Easter weekend. Michael Gove, the Education Secretary, will not be attending any of the conferences as he has told unions that he is on holiday. His deputy, Schools Minister Nick Gibb, will have to take any flak at the ATL and NASUWT conferences. (The NUT conference is traditionally a politician-free zone.)

The teachers' unions, though, will be lining themselves up for a longer ball game.

The classroom campaign

Monday, 18 April ATL conference begins with call for an investigation into why growing numbers of girls are being excluded from school.

Tuesday, 19 April Debate on strike action over pensions threat – the first time ATL has ever called for a national strike.

Wednesday, 20 April Schools Minister Nick Gibb makes his first appearance at a teachers' union conference.

Saturday: 23 April NUT debates motion on public spending cuts – "not a single job should be lost".

Sunday, 24 April Both NUT and NASUWT debate the pensions crisis.

Tuesday, 26 April Christine Blower, general secretary of the NUT, issues her rallying call to the troops as they disperse to go back to the classroom and campaign for support for industrial action.