A cross-party group of MPs has called for a change in the law that allows adults in positions of trust, from sports coaches to faith leaders, to legally have sex with children aged 16 and 17 in their care.

At present, the law allows only for adults in certain jobs to be prosecuted, such as teachers and social workers. Roles that fall outside this definition of “position of trust” include private tutors, driving instructors and coaches in after-school clubs, as well as vicars, imams and other religious leaders.

A report published by a cross-party group of MPs called for this “legal loophole” to be closed.

Sarah Champion, the Labour MP for Rotherham who chaired an all-party parliamentary group on the issue, said: “It makes no sense that young people should be protected from grooming and sexual abuse at school but not at their church or football club.

“Children attending youth groups at their church, participating in a gymnastics team or having driving lessons are vulnerable because the current law does not prevent the adults supervising them from engaging in sexual activity.”

The campaign to amend the Sexual Offences Act 2003 began in 2016 after the Guardian’s revelations about sexual abuse in football.

The former sports minister Tracey Crouch agreed at the time that the legislation should be extended to include sports coaches but this has not happened. The Ministry of Justice said earlier this year it was reviewing the law.

A Freedom of Information request found 653 cases where adults who could be regarded as being in a position of trust had a sexual relationship with a 16- or 17-year-old between 2014 and 2018.

Of the 495 cases where the adult’s role was recorded, the majority (31%) were in sport and 14% were in religious settings. The data showed that such incidents increased in both settings over the four years.

The legal age of consent in the UK is 16, meaning teenagers this age can lawfully decide who to have a sexual relationship with. However, campaigners argue that this ignores the power imbalance present in religious settings, sports clubs and other youth activities.

The MPs’ report was supported by major Christian groups, including the Church of England and the Methodist Church, as well as at least one Islamic group and children’s safeguarding charities, such as the NSPCC.

Andrew Fellowes, the NSPCC’s public affairs manager, said: “It makes no sense that children are protected from predatory adults in some settings but not others. Yet it has now been more than two years since government first said that they would address this glaring safeguarding problem and all this time young people remain vulnerable to adults who want to abuse their power.

“Any adult who is in a position of authority over a young person should not be allowed to exploit their role, which is why we’ve been urgently calling on government to close this loophole and make sure that all children are protected.”