There were nearly 730 teacher vacancies in Scotland’s schools as pupils returned after their summer break, figures have shown.
A freedom of information request by the Liberal Democrats showed 388 primary teacher vacancies and 341 for secondary schools as of 9 August.
Argyll and Bute recorded the most vacancies at 200.
The Scottish government said the figures represented only 1.5% of the total workforce.
The area with the second highest vacancy rate was Aberdeen, where 86 vacancies were recorded, followed by the Borders at 47.
Liberal Democrat education spokesman Tavish Scott said teachers would be “dangerously overstretched” unless action was taken to address the shortages.
His party has called for a penny increase in income tax in order to raise money for education spending.
He said: “Thousands of pupils faced the prospect of going back to school without a dedicated class teacher in place.
“This can only increase pressure on other teachers and make life more difficult for those pupils who need the most support.”
A Scottish government spokeswoman said ministers wanted the “right number of teachers with the right skills” .
She added: “Where there is an issue, this tends to be in specific areas where local factors, such as house prices, can be an important part of the problem.
“We are spending £88m this year to make sure every school has access to the right number of teachers.”
the spokeswoman said that teacher vacancies arose across Scottish local authorities “continuously throughout the year”.
“These figures represent less than 1.5% of the total workforce and in the time since they were compiled many of these vacancies will have been filled”, she said.