A teaching union is to stage a series of one-day strikes as it steps up its dispute over pay and conditions.
The NASUWT will target small clusters of schools in and around Glasgow with strike action from 23 November.
The union said the move was “driven by the significant financial detriment teachers have suffered as a result of six years of pay freezes and pay cuts”.
Glasgow City Council said it viewed the action as illegal and was taking advice “with a view to having it stopped”.
The Scottish government described the union’s decision as “deeply disappointing” and said industrial action was “not in the interests of anyone, least of all pupils and parents”.
The union had already put in place industrial action short of a strike, with members refusing to exceed their working hours or undertake administrative tasks.
Plans drawn up
NASUWT said teachers had not received any pay award since April 2016 and the pay award for 2017/18 was more than six months overdue.
Teachers at St Andrew’s Secondary School, Eastbank Academy and All Saints Secondary School in Glasgow will be the first to strike on Thursday 23 November.
The following week, action is due to move to Kirkintilloch High School, Lenzie Academy and Bearsden Academy in East Dunbartonshire.
Further strike action for next term in other schools, including primary schools in other local authorities, is expected to be announced over the coming weeks, with plans being drawn up for an escalation of the action short of a strike.
General secretary Chris Keates said: “Teachers regret having to escalate action and the disruption this will cause to pupils and parents but more and more teachers are now saying that enough is enough and are reaching the end of their tether over workload, pay and other conditions.
“The NASUWT has sought to engage constructively to address these issues through the teachers’ negotiating machinery but this has shown itself to be increasingly not fit for purpose, as, year on year, deals have been struck which have cut teachers’ pay and worsened their conditions of service.
“Whilst the NASUWT’s direct dialogue with ministers has secured some progress on tackling workload, the government regrettably failed to capitalise on that progress and ensure that employers and schools take workload reduction seriously.
“Teachers’ pay and conditions of service are inextricably linked to the high quality of educational provision for all children and young people.
“Attacks on teachers’ pay and conditions of service are attacks on our children and young people.
“Our rolling programme of strikes will be a regular reminder to the government, employers and the public of the plight of the teaching profession.”
The Scottish government said the strike action was inappropriate, given that pay talks were ongoing.
A spokesman said: “Teacher pay negotiations are currently under way with local councils, as the employer, and the Scottish government fully involved.
“To strike while these talks are continuing is not appropriate.”
Scotland’s largest teaching union, the EIS, said it remained committed to negotiations on this year’s pay settlement
A spokesman said: “This proposed strike action by the smallest STUC-affiliated teacher trade union in Scotland is news to the EIS.
“Negotiations on this year’s pay settlement are ongoing through the SNCT, which includes representatives of all affiliated teacher trade unions in Scotland.
“No trade union has demurred to the agreed teachers’ side pay strategy for this year during teachers’ panel meetings or full meetings of the SNCT.
“The EIS Executive, which meets on Friday, will consider this latest development and any potential response.”