Schools in John Swinney's constituency could be shut for a month following strike action

Unison said it has given notice to Perth and Kinross Council for the strike action by its members, after the largest local government trade union in Scotland rejected a national pay deal.

If the strike goes ahead, it would lead to the closure of some 50 schools and early learning centres for two weeks. The action would coincide with the start of the winter term on 21 October when pupils and staff are due to return from the autumn holiday, meaning schools could be closed for four weeks in total.

The union said it hoped that by targeting the action in Mr Swinney’s constituency of Perthshire North, it would “bring home to him the importance of finding a fair settlement” to the council pay dispute.

It comes after the union voted against the latest pay offer from local government umbrella body Cosla, which would see staff receive whichever is higher out of an increase of £1,292 per year or 3.6 per cent.

Council leaders in Scotland have already voted to impose the deal despite Unison’s opposition, saying that two other unions – GMB and Unite – have accepted it. Cosla has said the deal on offer is at the “absolute limit of affordability” given the tight financial situation across local government.

However, Unison said that its members are angry that the pay deal on the table lags behind that of other public services, with nurses and other NHS staff being given a 5.5 per cent wage increase.

Stuart Hope, Unison’s Perth and Kinross branch secretary, urged Mr Swinney to talk to union members on the picket line “to hear how undervalued council staff in his constituency feel.”

He said: “Taking action like this is the last thing school and early years staff want to do. Employees are taking this first stand on behalf of all local government workers because they’ve seen a decade of pay cuts and they see other sectors being offered deals of greater value.

“A fair pay deal should have been in place from 1 April but six months later it’s still not been agreed. Instead, the employer has imposed a wage rise rejected by a majority of the workers Unison represents. Yet again local government staff are being forced to strike to simply get fair pay.”

But finance and local government secretary, Shona Robison, said: “While this government respects workers' rights, no-one's interests will be served by industrial action which will disrupt children and young people attending schools and nurseries in Perth and Kinross .

“The pay offer is better than that made to local government workers in the rest of the UK and will see the lowest-paid workers, including Unison members, receive a 5.63 per cent pay increase.”

A Cosla spokeswoman said: “There is no further funding available to increase the value of the offer. We are aware that communities will be concerned about the detrimental impact industrial action would have, particularly for our children and young people.”