An SNP-run council has been accused of “deleting” Education Secretary John Swinney’s name from a controversial letter to teachers about classroom pay.

The Deputy First Minister initially co-signed the draft communication to teachers, but Glasgow city council snubbed him and put it out from their own education convener.

Labour MSP Iain Gray said: "With John Swinney becoming increasingly unpopular with teachers, it is no surprise that SNP-run Glasgow City Council deleted his signature from the letter.

Mr Swinney is embroiled in a bitter row with the trade unions over their demand for teachers' pay to be increased by 10%.

Council umbrella group COSLA, with the support of the Scottish Government, has offered 3% and strike action is on the horizon.

The Government has also suggested that an overhaul of the main grade scale, coupled with the 3% rise, would result in some teachers getting a boost in excess of 10%.

However, the disagreement was aggravated after the Government and COSLA agreed to go over the heads of the unions by sending a “joint communication” directly to teachers about the offer.

The Education Secretary wanted teachers to hear his side of the pay proposal before they voted in a consultative ballot.

The draft letter was co-signed by Mr Swinney and Tory councillor Gail Macgregor, who is COSLA’s resources spokesperson, and stated:

“We firmly believe that this is a fair offer which demonstrates that both Local Government and the Scottish Government value the teaching profession. We are disappointed that it has been rejected by the teacher unions.

“The teacher unions’ claim for 10% in a single year cannot be achieved. It is simply unaffordable, and the unions have been told this since their claim was submitted at the start of the year.”

They also said the pay offer and the grading restructuring amounted to a £105m investment in teachers.

However, when teachers in Glasgow received the letter by email, the names of Mr Swinney and Ms Macgregor had vanished. The signature of SNP councillor Chris Cunningham, who is the convener for Education, Skills & Early Years, appeared instead.

The wording was the same as the initial draft put together by COSLA and the Government, apart from an extra paragraph at the beginning:

“COSLA Leaders agreed that a joint letter from the Scottish Government and COSLA should be prepared and sent out to teachers explaining the pay offer to them.

“The information below is from the Scottish Government and COSLA which talks to the offer on the table and I would be grateful if you could share it with teachers in your school.”

Glasgow was a Labour bastion at a local authority level for decades, but the SNP won control of the council for the first time last year.

Around 20,000 teachers, many of whom are based in Glasgow, protested against Mr Swinney over the pay standoff at a rally in the city recently.

Placards included ‘Swinney is a ninny” and ‘Ebenezer Swinney’, which an education source said was an indication of the hostility to the SNP heavyweight by teachers.

A Council spokeswoman said: “Our City Convener for Education, Skills & Early Years, Councillor Chris Cunningham has sent a letter to schools which includes information from the Scottish Government and Cosla on the teachers' pay award proposal.”

A Scottish Government spokesperson said: “The Scottish Government has worked with COSLA to put in place the best teacher pay deal in the UK for 2018-19.

It is important that the component parts of the deal are explained in detail so that teachers have a full understanding of the proposals on the table.”