Construction of the replacement secondary has been hit by a number of delays since work began in autumn 2014.

It was originally anticipated that the school would open in August 2016, but as delays mounted this was postponed first to October 2016, then to Christmas 2016, then February 2017, before a completion date of April 2017 was announced.

This delay led to the City of Edinburgh Council moving to seek compensation from contractors O’Hare & McGovern in line with the terms of the contract.

The firm has now informed the local authority that it is unable to achieve the latest planned handover date of June 16 and is proposing a new date of August 11.

While O’Hare & McGovern considers that the school could still be occupied for the start of the new school year, the council has determined that it is in the school community’s best interests not to rush the completion by targeting a date so close to the new school year and has delayed the opening until after the Christmas holidays.

Previous construction delays to the project have been blamed on adverse weather and “challenging” foundation work.

Councillor Cammy Day, the council’s education convener, said: “I am extremely frustrated that once again we have been badly let down by our contractors. This new delay will be deeply disappointing for staff, pupils and parents alike. While this is not a situation any of us would choose to be in we must ensure we put the children’s interests first and foremost.”

Councillor Cathy Fullerton, education vice convener, added: “The council undertook an independent review of the contractors’ programme prior to the announcement of this most recent delay. In the circumstances I believe postponing the opening until January is the right thing to do. We will continue to monitor the works on site rigorously and ensure everyone with an interest in the school is kept up to date.”

A spokesman for O’Hare & McGovern said: “The delay in completing the contract is a source of disappointment.

“We are working closely with the council, and once the work is finished in August, Boroughmuir High School will be a fantastic, state-of-the-art education facility of which the staff, pupils, parents, and indeed Edinburgh, can be extremely proud.”