The teaching profession is divided over the first national teachers' walk-out over pay in 21 years, although a clear majority backs it.
An exclusive TES poll of just under 8,000 teachers in England and Wales found that six out of 10 felt the walk-out on April 24 was a good idea.
In our poll, support is strongest among members of the National Union of Teachers, which is organising the industrial action to press for a pay increase in line with inflation. But among members of other teacher unions - which represent more than half of the workforce - views were more divided: 53 per cent say it is a good idea, while 47 per cent disagree.
Nearly half of all the teachers who responded felt their schools would be forced to shut for the day.
The NUT has argued that the Westminster government's proposal to increase teachers' salaries by 2.45 per cent this year, and 2.3 per cent in the two following years, is a pay-cut in real terms. It is calling for a pay rise of at least 4.1 per cent.
Seven out of 10 of the NUT members polled by The TES said they would be walking out.
Mary Compton, a teacher from Radnor, Powys, and a veteran of teacher strike action in the 1980s, said: "We are at last waking the sleeping giant, which is our union's ability to take strike action and defend state education."
But support elsewhere in Wales was muted, with other teaching unions saying there was nowhere near the appetite for militant action as there was in the late 1980s.
Geraint Davies, policy officer for the NASUWT Cymru, was a teacher involved in industrial action at the time.
He said: "Pay is so much better now than back then. The NASUWT Cymru believes what is being offered is fair in the current climate, but back in the Eighties teacher pay was very low.
"There was deep anger by the teaching profession back in 1987 - it was raw - but not now as pay is so much better."
But Mr Davies does see discontent over rising workload, as well as lack of funding, as potentially inflammatory issues among the Welsh teaching force over the next 12 months.
Members of the union's Vale of Glamorgan branch have now lifted a threat of strike action after the local authority increased funding by an average of 3.8 per cent following their pressure.
Gruff Hughes, general secretary of Welsh-medium teaching union UCAC, said: "We asked our members and they overwhelmingly decided not to strike. But we have great respect for the NUT's decision, and support it in the sense that our teachers will not be taking part in any action that has an adverse effect on their strike."
"I think 20 years ago there was more general consensus about taking strike action than now, but I don't think it will create friction between teachers."
Andrew Smith, a maths teacher at a comprehensive in Birmingham, said he had supported the strike, although he was more concerned about pupil behaviour.
"Pay is the one thing that unites teachers on all levels though, so striking on that issue could draw attention to other things," he said.
However, several NUT members who voted against the strike have already started to switch to other unions, as they did during industrial action in the 1970s and 1980s. Voice, formerly the Professional Association of Teachers, was established in 1975 as a non-striking union.
Philip Parkin, general secretary, said: "Past strikes have led to teachers reappraising their situation, and some NUT members will decide they are not happy with their union's actions."
The Government is not going to back down, so it seems a rather pointless exercise."
The Department for Children Schools and Families has said it was "clear" that most teachers did not want a dispute.
A department spokesman said: "The union's ballot shows that strike action was backed by less than a quarter of the NUT members - only around one in 10 of the overall teacher workforce."
Education minister Jane Hutt said: "Although teacher's pay and conditions of service are not devolved to Wales, I am naturally concerned."
David Evans, secretary of the NUT Cymru, said the strength of feeling of Welsh members over pay was strong. He said rallies would be organised in both the North and South of Wales.
Steve Sinnott, the union's general secretary, said he did not want to see a "return to the bad old days". However, he said the worsening economic climate, witnessed in the boom and bust era of the Eighties, could lead to low staff morale and fuel discontent.
In the NUT ballot, just over three-quarters voted for strike action, with just under a quarter voting for none - a total of 64.101 members. Turn-out was 32.2 per cent.
Strike coverage, page 6. Are teachers really paid badly? TES magazine.