The general secretary of the NUT has warned that the union could take national strike action if the government does not make extra funding available to schools.
At a press conference this morning ahead of the NUT's annual conference next week, Kevin Courtney was asked what action the union could take to oppose cuts to school budgets.
"National strike action is a possibility," he said.
"The barriers to national strike action are higher than they have been previously, but the degree of mobilisation amongst teachers is also I think higher than it’s been previously."
Under the 2016 Trade Union Act, unions in certain public services, including education, have to get 50 per cent of members to return their ballot papers and 40 per cent of all members to vote "yes" before national industrial action can take place.
Mr Courtney said a strike was not an immediate prospect, and that November's Budget would be a key factor in deciding what action is taken.
Industrial action 'not ruled out'
"I think the government has to put money into the schools in that Budget. I think there’s going to be tremendous pressure on government to do that," he said.
"Industrial action is not ruled out, but national action is not where our planning horizon is at the moment. We're planning on creating the biggest possible noise between now and that Budget so that money comes into schools."
The NUT was "hearing screams from our members" about the cuts, he said, and industrial action would be a "completely legitimate response to that".
Mr Courtney said he believed that the union could get over the double threshold: "It’s astonishing the level of difficulty that government has tried to put in the way of unions calling industrial action, but if they don’t move on this question, if these cuts just carry on then I think it’s not ruled out that we can beat those thresholds and have that sort of industrial action".
The NUT is due to formally begin transitioning to a new union in September, the National Education Union, following a vote to merge with ATL last month.
During the press conference, Mr Courtney also revealed that Labour's shadow chancellor, John McDonnell, has been invited to speak at the NUT's conference.
Asked why the union had not invited a member of the government to speak, Mr Courtney said: "I think the question is more why have we chosen to invite John McDonnell, because we haven’t been inviting politicians for some time."
Although Labour leader Jeremy Corbyn addressed the conference last year, Mr Courtney said the union had generally refrained from inviting politicians in recent years because "our conference has wanted to spend its time talking about what the union's doing" and "people thought that politicians just weren't listening to teachers".
"Now we are think there are some politicians who are listening, so we want to listen to them," he added.
"It doesn’t mean that we will find ourselves in agreement with everything they say, but there seems to be some point in having some dialogue with them because there is some degree of mutual concern."