Plans to close Oxford's last remaining state girls' school, and move it into a caretaker's house and temporary classrooms, have been branded "disgraceful" by a former Lord Mayor.

Supporters of Milham Ford School, in Marston, have reacted angrily after the school's headteacher Anne Peterson revealed the school's 150 staff and pupils could be decamped into a converted house and mobile rooms at Oxford School, in east Oxford, as part of the re-organisation of the city's education system.

Oxfordshire County Council is hoping to raise around £10m by selling off the Milham Ford site. The money will help pay the £35m bill for introducing a two-tier education system, which will involve closing Milham Ford and the city's middle schools. It was hoped the school would share part of a £4.5m building at Oxford School's Glanville road campus, after leaving its current site next year.

Former Lord Mayor of Oxford Maureen Christian, who represents Marston ward, has been a critic of plans to close the 100-year-old school.

She said: "Putting the school into temporary accommodation is quite ridiculous. The school is doing excellent work, and this is outrageous.

"The county council is behaving disgracefully by selling the school to fund the change to two-tier education. It has rushed the reorganisation through too quickly and has not given adequate care to all the schools. Children are only educated once and by doing this they are putting pupils' education at risk."

Janet Todd, a former city and county councillor, and former chairman of governors at Milham Ford School, said Oxfordshire's out-going chief education officer Graham Badman had treated Milham Ford disgracefully.

Tom Long, a county council education spokesman, said no decisions had been made over the school's future accommodation.