Strikes by teachers in England and Wales will go ahead this week after last-ditch talks between union leaders and the government broke up without any progress. Teaching union leaders accused the education secretary, Gillian Keegan, of squandering the opportunity to avert strike action as they emerged from talks at the Department for Education on Monday. Members of the National Education Union (NEU) will walk out on Wednesday, in the first of seven days of strike action that is expected to affect tens of thousands of schools and potentially millions of pupils. The meeting lasted a little over half an hour, after which the NEU joint general secretaries, Dr Mary Bousted and Kevin Courtney, said: “Gillian Keegan has squandered an opportunity to avoid strike action on Wednesday.” They accused the government of being unwilling to seriously engage with the causes of strike action. “Real-terms pay cuts and cuts in pay relativities are leading to a recruitment and retention crisis with which the education secretary so far seems incapable of getting a grip. “Training targets are routinely missed, year on year. This is having consequences for learning, with disruption every day to children’s education. We can do better as a nation, for education, for our children, if we invest more. That is in the gift of this government. It should start with a fully funded, above inflation pay rise for teachers.” While Wednesday’s action will go ahead, the door has been left open for further talks before the next day of strike action in England on 28 February, but there is little to suggest that the government will come up with an offer that will meet teachers’ demands. A new poll of teachers suggests that up to three in every five schools in England could be closed or partially closed to pupils by Wednesday’s strike action. Teacher Tapp, a daily surveying app, polled almost 8,200 teachers on Sunday, of whom 14% said their school was planning to close to all pupils, while 44% said their school would close “for some pupils”. London schools look set to be among the most disrupted, with 23% of teachers polled in the capital said their schools would close for all pupils. The NEU is also concerned that the government missed last week’s deadline for submitting its evidence to the teachers’ pay review body on next year’s pay, prompting fears that their latest pay recommendation is likely to further enrage teachers. “We did not get anywhere,” Bousted later told the Guardian. “It’s like trying to nail jelly to a wall. We did say we are serious about negotiations and are prepared to look at a whole range of ways to resolve the dispute. But we are nowhere near a solution right now.” Keegan said it was “hugely disappointing” that the NEU is going ahead with strike action and pledged to do everything possible to protect children’s education. “These strikes will have a significant impact on children’s education, especially following the disruption of the past two years, and are creating huge uncertainly for parents. “With talks ongoing on a range of issues, including around future pay, workload, behaviour and recruitment and retention, it is clear that strikes are not being used as a last resort.” NEU members will now join train drivers, civil servants, university lecturers and other staff, bus drivers and security guards from seven trade unions in the biggest day of industrial action in over a decade on Wednesday. The NEU says Wednesday’s action will affect an estimated 23,400 schools in England and Wales. Two other teaching unions, which also balloted their members, narrowly missed the 50% turnout threshold required for strike action. The NEU has seen an influx of new members since its successful strike ballot. Bousted said by last Friday an additional 34,000 teachers had joined, and with more over the weekend. The union is demanding a fully funded above-inflation pay rise. Teachers were awarded an average pay rise of about 5% by the government – with new teachers awarded a bigger increase – but with inflation in double digits, it amounts to a significant real-terms pay cut for many staff. According to the Institute for Fiscal Studies, senior teachers have in effect seen their pay decline by £6,600 since 2010.