Story focusing on parents who refuse treatment for their son's illness will be published in September

Ian McEwan will focus on the contested domains of religion and family life for his forthcoming novel, The Children Act, according to his publisher Jonathan Cape.

Due to be published on 4 September 2014, The Children Act puts ideas of adult responsibility on trial with a plot that revolves around parents who are refusing treatment for their sick son because of their religious beliefs. The novel centres on the presiding judge at the high court, who is a woman.

Speaking at last month's Oxford literary festival, McEwan described the denial of medical help on religious grounds "utterly perverse and inhumane", according to the Telegraph, arguing that "the secular mind seems far superior in making reasonable judgments".

"There's an almost consumerist notion that the pursuit of individual happiness cuts across the interests of children," McEwan said.

Citing cases involving Jehovah's Witnesses and Catholics, McEwan praised the 1989 Children's Act, which enshrines the child's welfare as the "paramount consideration" in any court ruling, calling it a "remarkable and civilised piece of legislation".

The novelist has long been suspicious of organised faith, telling the Believer in 2005 that he has "no patience whatsoever" with religion.

"I'm not against religion in the sense that I feel I can't tolerate it," he said, "but I think written into the rubric of religion is the certainty of its own truth. And since there are 6,000 religions currently on the face of the Earth, they can't all be right. And only the secular spirit can guarantee those freedoms, and it's the secular spirit that they contest."

According to McEwan's publisher, Dan Franklin, the new novel is "classic McEwan, demonstrating yet again his extraordinary ability to speak to both head and heart."

The novelist launched a career which has combined critical acclaim and bestselling success in 1975, with a collection of short stories which touched on child sexual abuse, First Love, Last Rites. The Cement Garden was published in 1978, the story of a brother and sister who bury their mother in the cellar and leave civilisation behind. McEwan won the Booker for the first time in 1998 with Amsterdam, the story of two friends who plot each other's murder, and has been shortlisted a further four times.