Supply teachers have rubbished plans for supply staff to be brought in to keep schools open in the event of a strike.
Both the NEU and NASUWT teaching unions said last week that they were prepared to ballot members on strike action over pay.
But it has been reported that government officials are drawing up plans for supply staff to cover for teachers if this takes place.
And last week, the government unveiled plans to overturn a law banning organisations from hiring temporary agency workers to plug gaps left by striking employees.
However, school leaders and education figures have been quick to highlight a chronic shortage of supply staff.
And now, the chair of a network of nearly 2,500 supply teachers has written to the education secretary suggesting that most staff will not be willing to cross picket lines to cover for striking workers, and warning that the plans to bring in temporary cover “denigrate” his members.
In a letter sent this weekend, Niall Bradley, chair of the National Supply Teachers Network, said that only a tiny proportion would be willing to work if a strike took place, telling the education secretary: “Your maths doesn’t add up.”
In his letter, Mr Bradley said that he knew his members well, and was “pretty sure” that most would not cross a picket line, adding that the majority were NEU or NASUWT members themselves.
He ran a poll of more than 300 members, with just 3 per cent indicating that they would cross the picket line, and 92 per cent saying that they would not.
In the letter, he added: “If only one of the teaching unions were to go on strike, there would not be enough supply teachers to cover the striking teachers.
“So please, do not denigrate supply teachers any further in the eyes of our permanent colleagues by suggesting we would help break their strike, should it go ahead.”
Mary Bousted, joint general secretary of the NEU, echoed the claims in the letter, suggesting that the mooted plans would not cover staff if strikes were to take place.
She said: “We do not expect this latest wheeze to play out any differently. Supply teachers already feel exploited, without the government adding insult to injury.”
“Instead of trying to dodge the problems at the heart of poor pay, high workload and a recruitment and retention crisis, the government would do well to listen to the NEU’s concerns and make some effort to act on them.”
Plans - briefed to a national newspaper - for an “army” of supply staff to cover for striking workers was an example of “sabre-rattling” by a government that had been unable to summon retired teachers back into the classroom at the height of the Omicron wave, she said.
Practical difficulties with supply cover plan
Individual supply teachers have told Tes that they would not be willing to break the picket lines if strike action took place.
Chris Dicken, a supply teacher based in Northamptonshire, said that he agreed with the strike action, and that he had spoken to other supply staff who had said the same.
He also pointed to practical difficulties with the idea of supply staff covering for those with permanent posts.
He said: “I cannot see how this would work. Supply teachers nowadays rely on the teachers in schools in terms of the technology that’s used, and how that is set up, or the planning is more or less done months in advance.
“I can’t see how - other than babysitting - an army of supply teachers would get the work done.”
Asked to respond to the claims in the letter, the Department for Education reiterated education secretary Nadhim Zahawi’s previous comments on strike action.
Speaking last week, Mr Zahawi said: “We have proposed the highest pay awards in a generation for new teachers - 16.7 per cent over the next two years - alongside further pay awards for more experienced teachers and leaders.
“Young people have suffered more disruption to their education than any generation that’s gone before, and it’s the vital work of teachers that is helping them get back on track. The last thing I - or any parent - want to see is anything that would risk undoing that progress.
“We will be considering the pay recommendations from the independent pay review body in due course.”
Last week, the NEU warned the education secretary that it would ballot members over strike action in the autumn if the government fails to commit to a pay rise above inflation, which stands at 9.1 per cent today.
Leaders of NASUWT called for a 12 per cent pay increase for teachers this year, and said it would ballot members in England, Wales and Scotland for industrial action if such a pay rise was not offered.
