Scotland’s biggest teaching union has announced dates for further strikes in an escalation in its standoff with the Scottish Government and councils.

The Educational Institute of Scotland (EIS) said action will take place over 16 consecutive days in January and February, with teachers in two local authorities walking out each day.

The action will start – unless a deal is agreed before then – on January 16 and is due to last until February 6.

General secretary Andrea Bradley praised the teachers who took part in the first strike on Thursday, saying they had been angered by the conduct of the Scottish Government and local authority body Cosla in presenting their latest offer.

National strike days will also take place on January 10 for teachers in primary and special schools, as well as early years, and on January 11 for those working in secondary schools and secondary special schools.

Announcing the latest action, Ms Bradley said: “The EIS will move ahead with our previously announced two additional days of national strike action in January.

“We can also now confirm that Scotland’s teachers will strike on 16 consecutive days in January and February, with teachers in two local authorities on strike on each of these 16 days.

“We have been forced into the escalation of this action by the lack of willingness to negotiate properly and to pay teachers properly, by a Government that says it wished to be judged on its record on education.

“The judgment of Scotland’s teachers on the matter of pay is clear, with the first programme of national strike action that we have engaged in for four decades.

“It is now for the Scottish Government and Cosla to resolve this dispute, and prevent further strike action, by coming back to the negotiating table with a substantially improved pay offer for all of Scotland’s teaching professionals.”

The Scottish Government submitted a pay offer to teachers earlier this week which was summarily dismissed by the unions.

Under that proposal, teachers earning under £40,107 would receive an increase of £1,926 per year – 6.85% for those on the lowest salaries – while those on more would get 5%.

The Government has insisted it has no more cash for pay offers, with Scottish Education Secretary Shirley-Anne Somerville saying any increase in funding would have to come from elsewhere in the budget.

The EIS has been pushing for a minimum of a 10% increase.

Scottish Labour education spokesman Michael Marra said the announcement of further dates was “inevitable” after the rejection of the previous offer and called on Nicola Sturgeon to take part in negotiations.

“That offer had sat on the Cabinet Secretary’s desk for weeks and was only signed off with hours to go before the first all-out teachers strike in 40 years,” he said.

“The Scottish Government has badly mishandled the most critical round of public pay negotiations in decades.

“Money should have been in the budget for public sector pay deals at the start of the budget year. Instead we now have a crisis that is escalating fast.

“A deal must be struck to avoid these strikes taking place.

“The First Minister must personally come to negotiating table to get a deal done where the Government has failed to dreadfully so far.”

Scottish Conservative education spokesman Stephen Kerr MSP said the Scottish Government is to blame for the renewed strike action.

“Shirley-Anne Somerville has been asleep at the wheel,” he said.

“She dithered and delayed for two months before finally making another pay offer earlier this week, which was then rejected within an hour.

“The Education Secretary has shown that she lacks the leadership required to resolve disputes satisfactorily.

“The SNP’s dereliction of duty gives the lie to their claim that education is a priority.

“They didn’t engage with the teaching unions despite having known this crisis was coming. This is a shocking failure that threatens to have damaging consequences for pupils and cause enormous inconvenience for parents.”

Education Secretary Ms Somerville said: “It is very disappointing that the EIS has rejected the latest offer, which is fair and progressive and mirrors the deal accepted by other Local Government workers.

“The latest offer – the fourth which has gone to unions – would have meant a 21.8% cumulative increase in teacher pay since 2018. The starting salary for a fully qualified teacher would be £35,600. That’s £7,650 more than their counterparts in England.

“It is simply unaffordable to have a 10% increase which unions are asking for within the fixed budget which the Scottish Government is working in.

“I recognise the strength of feeling within the unions but they also need to recognise that the Scottish Government budget is fixed and is already committed. any new money for teacher pay would have to come from elsewhere in education.”