Richmond Inclusive Schools Campaign (Risc) and the British Humanist Association will not challenge the High Court’s decision to back Richmond Council.

The ruling that the council had acted lawfully in its decision to allow the Diocese of Westminster to open a Catholic school in Twickenham was officially published this week.

Risc spokesman Jeremy Rodell said: “Anyone who has followed this story for the past 18 months and who reads the judgement will see there are a number of aspects that are open to challenge.

“But we recognise that it is not practical to appeal against it. Apart from the fact that we could not bear the costs, any appeal would not be heard until after places at the new schools had actually been offered for the next school year.

“We have no desire to risk that level of uncertainty for parents and children, and it is unlikely that, even if we won an appeal, a judge would stop the schools going ahead at that stage.”

The case hinged on a new section of the Education Act that became effective in February this year. It says that “If a local authority in England thinks a new school needs to be established in their area, they must seek proposals for the establishment of an academy”.

New faith-based academies and free Schools only receive Government funding if they have a maximum of 50 per cent faith-based admissions.

Richmond Council decided in May to go ahead with a Catholic voluntary aided secondary school, which means that up to 100 per cent of places could be prioritised for Catholic children.

In his written submissions, Mr Justice Sales said: “It is clear that Lord True was not addressing the technical question of ‘need’ as that term is used in section 6A, but was speaking more generally about the desirability of introducing Catholic schools into the borough… Nor do I consider that anything said in the consultation paper or associated questionnaires was liable to mislead the public into thinking that the council thought there was a ‘need’ (in the section 6A sense) for new Catholic schools, in circumstances where (as I find to be the case) it did not.”

Mr Justice Sales accepted the argument of the Secretary of State for Education, who intervened in the case, that local authorities were free to approve new voluntary aided schools without having to seek academy proposals.

Lord True, leader of Richmond Council, said: “This written ruling has now hopefully removed the last obstacle put up by those working to block the creation of two new schools for hundreds of local children.”