All of the primary schools in Perth and Kinross are closed after non-teaching school staff began strike action in First Minister John Swinney's constituency.
Members of the union Unison, which includes janitors and classroom assistants, have walked out over pay for all council workers - meaning 50 schools and early years centres will be closed today and could remain closed for two weeks.
The union has targeted the first minister's constituency with hopes of putting pressure on Mr Swinney.
The latest pay offer - an increase of either 3.6% or £1,292 - was made in August to see off the threat of bin strikes and it was accepted by GMB and Unite but not Unison, the biggest council union.
All secondary schools will be open except St John's Academy in Perth and the Community School of Auchterarder.
The council said it was not possible to complete risk assessments in advance due to the October holidays, so it had to close all primary schools and early years centres - but the situation will be reviewed daily.
It said the situation could change on a day-to-day basis, and parents and guardians should refer to the council website for updates.
Before and after school care will also be closed and payments will be made to families whose children are eligible for free school meals.
The walkout by Unison members is due to begin immediately after the two-week October school holiday, meaning schools could be shut for a full month
Both the Scottish government and council body Cosla said no more money for pay deals was available this year.
The GMB and Unite wanted their members to get the 3.6% rise they voted for as soon as possible. This would be backdated to April.
However, Unison has warned of a national strike ballot if the dispute is not resolved.
The union believes more needs to be done to address what it sees as the long-term decline in the value of council pay.
It argued that council staff have seen the value of their pay fall by 25% over the last 14 years and said councils have faced problems recruiting staff for some roles.
Finance Secretary Shona Robison said: "No one's interests will be served by industrial action which will disrupt children attending schools and nurseries".
And councils said using any more of their money for pay would mean further cuts to services or job losses.