Church leaders, faith groups and pro-life organisations have formed a coalition to oppose the extension of abortion time limits in Scotland.

The group, co-ordinated by the Society for the Protection of Unborn Children (SPUC) Scotland, is supported by the Catholic Church in Scotland, the Muslim Council of Scotland and the Free Church of Scotland, among others.

Abortion law is to be devolved to Holyrood under the Scotland Bill, the package of powers aimed at delivering on the recommendations of the post-referendum Smith Commission.

Opponents to the move, including Labour and women's rights groups, had warned it could undermine the consensus on the current time limit of 24 weeks.

The Don't Stop A Beating Heart group said it was concerned that the move would lead to an extension of the time limit, despite the Scottish Government stating it has no plans to change the law.

The campaign says it has brought Scotland's pro-life groups under the same banner for the first time and is "a significant show of strength."

Pro-choice organisations have said the transfer of the power could lead to more "progressive" legislation north of the border.

John Deighan, chief executive of SPUC Scotland and campaign co-ordinator, said: "The rights of the unborn child are facing new threats with the impending devolution of powers to the Scottish Parliament from Westminster.

"Already, well in advance of the transfer of legislative authority, we are hearing a clamour for further extension of the existing, excessively liberal law.

"This could see abortion legalised from the existing 24-week limit, in most cases, up until the point of birth.

"In response to these deeply disconcerting demands, pro-life supporters from different backgrounds, people of faith and none, in addition to concerned organisations and individuals have decided that we must stand together in the face of this onslaught."

Scotland's most senior Catholic archbishop, Philip Tartaglia, said: "I wholeheartedly support the aims of the Don't Stop A Beating Heart campaign to defend and protect unborn human life and to call legislators not to further extend abortion time limits."

Free Church of Scotland moderator Rev David Robertson said the church was happy to join an alliance "which will spread the fight for justice in a bid to influence legal attitudes to the right of life".

Muslim Council of Scotland director Salah Beltagui said: "We are committed to defending all human life and I genuinely believe that we will prevail in this crucially important fight for the rights of unborn children."

The coalition also includes the Abortion Recovery Care and Helpline, Christian charity Care and Cardinal Winning's Prolife Initiative.