The country’s largest teaching union warned a walkout would be “inevitable” if ministers and councils do not back an inflation-busting salary increase.

The Educational Institute of Scotland (EIS) has said anything less would be “unacceptable” ahead of talks.

Its demand comes after the country plummeted down league tables in literacy and numeracy.

But leaders have warned of an ongoing recruitment crisis and growing pressure due to heavy workloads.

Hundreds of schools could be forced to close, creating a headache for parents over childcare. 

Scottish Tory education spokeswoman Liz Smith said the threat was “deeply regrettable”.

She added: “Any industrial action inevitably damages the education of young people and puts considerable pressure on parents and other local services.

“Everyone recognises this is a very tough economic period when it comes to basic pay and pensions but these concerns must be addressed by negotiation and not strike action.”

In 2011, industrial action over pension changes shut most schools and nurseries, affecting 600,000 children.

But the last time the sector held a strike on pay was in 1986 sparking chaos for parent and pupils. 

The Scottish Negotiating Committee for Teachers, which local authority employers and Scottish Government representatives, is due to decide the 2018/19 pay settlement.

The EIS, which represents more than 80 per cent of teaching professionals, wants wages to be “restored to pre-austerity levels”.

Finance Secretary Derek Mackay has pledged to lift the 1 per cent public sector pay cap.

He has said he will provide a 3 per cent pay rise for NHS staff, police, teachers and others earning up to £30,000 and 2 per cent for those earning more.

But EIS general secretary Larry Flanagan said the 2 per cent “offer” will not be acceptable. 

He added: “The clear message that teachers wish their employers and the Scottish Government to hear is that ‘enough is enough’ and that the era of real-terms pay cuts must end.

“For far too long, teachers have been paying the price of austerity-driven cuts prompted by a financial situation that was not of their making.

“This has led to a decade-long decline in teachers’ pay with serious implications for teacher recruitment, retention and for education provision across the country.” 

Scottish Labour’s education spokesman Iain Gray warned failure to reach a deal would see SNP ministers “reap what they have sown over 10 years of incompetence”. 

He said:  “Scottish pupils face a year of chaos and disruption unless the SNP government delivers improved teacher pay and workload this year. 

“What our schools really need are enough teachers with enough time, support and resources to do their job; with a career structure to properly recognise their efforts.

“That means a significant improvement in pay, career structure and workload, properly funded by government to re-establish the Scottish profession as world leading.”

A spokesman for the local government body Cosla said: “We look forward to the discussions in relation to teachers’ pay starting in early January.

“As employers we endeavour to ensure that the pay deals we reach within all our bargaining groups are fair and also sustainable.” 

The Scottish Government said it was working “to improve pay and conditions”.

A spokeswoman added: “We have already taken action to reduce workload and have agreed a backdated 1 per cent pay rise from April and a further 1 per cent uplift from January until the end of March 2018 - backed by an additional £24 million in the draft Budget.

“And the education reforms being implemented by this government will create new opportunities for teachers to develop their careers.

“We will also, alongside employers and unions, take part in a strategic review of pay and reward.”