Perth and Kinross Council has pledged £4.2 million to allow Perthshire pupils to continue being taught in a Dundee secondary school.
PKC said it had been advised by Dundee City Council that Harris Academy would no longer be able to accommodate pupils from August 2023.
The PA revealed the proposal last week, with councillors giving it their backing at a lengthy meeting of the full council on Wednesday, October 6.
The proposal could help fund an extension at Harris to help accommodate Invergowrie pupils at the Perth Road school.
It is understood Dundee City councillors will make a final decision on their statutory consultation later this month.
In an update to PKC’s capital budget - set in September 2020 - council leader Murray Lyle asked councillors to approve this further investment in PKC’s capital investment programme.
The Conservative leader said: “While pupils at Invergowrie Primary School sit within the catchment area of Perth High School, under a long-standing arrangement, they have been awarded entitled status by Dundee City Council to attend Harris Academy.
“As a result of this arrangement, there are limited transport costs for this council due to Harris Academy being within the statutory walking distance for Invergowrie pupils.
“Any change to that arrangement would result in pupils undertaking a 55-minute bus journey each way to Perth High School at an estimated annual cost of £120,000 per annum.
“Over the 50-year period, this works out as an additional £13.7 million.
“ Perth and Kinross Council considers that the significant difference in travel time, the longer school day, the impact on after-school activities and time for homework etc. would have an adverse impact on Invergowrie pupils.”
He added: “I am aware that this is in line with the wishes of the vast majority of parents of pupils attending Invergowrie Primary School and will, I am certain, be warmly welcomed by them.”
The move was approved as part of a wider budget paper.
PKC’s lifelong learning convener Conservative councillor Caroline Shiers said: “Parents and young people in Invergowrie will be delighted that - if Dundee City Council agrees - pupils will still be able to attend Harris Academy.
“Not only does it mean they can still attend the secondary school closest to their homes, but the reduced travel will be better for the environment by cutting emissions.”