Education Secretary Nicky Morgan has labelled a Jewish community’s decision to ban women driving “completely unacceptable”.

Leaders of the north-west London Belz sect, part of an ultra-orthodox branch of Haredi Judaism, reportedly sent a letter telling parents their children would be prevented from attending school should their mothers’ drive.

The letter, seen by the Jewish Chronicle, claimed that female drivers were “contrary to the rules of religious modesty” and warned that from August children at the school in Stamford Hill would be turned away if their mothers violated the policy.

Ms Morgan, also minister for women and equalities, said of the notice: “This is completely unacceptable in modern Britain.

"If schools do not actively promote the principle of respect for other people they are breaching the independent school standards,” she said in a statement to the Guardian.

The Department of Education confirmed that an investigation was underway.

The school, one of two run by the Belz community in the area, has been rated “Good” by Ofsted in the past.

Belz leaders in Stamford Hill said children would be banned from its schools if their mothers drove (Getty)

Ahron Klein, chief executive of the schools, defended the “religious principles” and “strong traditional values” of the community but claimed the notice had not intended to "stigmatise or discriminate against children or their parents".

“We are proud of what we stand for and we do not feel the need to excuse ourselves for our deeply held beliefs and staunchly maintained way of life. It has withstood the test of time and is not prone to the vagaries of passing fads,” he wrote in response to Mrs Morgan’s letter.