A new push for control over abortion to be handed to Scottish ministers is to be launched by peers.

The Conservative government has already pledged to beef up plans to give greater powers to Holyrood.

Recent comments by Tory Scottish Secretary David Mundell also suggest that supporters of the change could be pushing against an open door.

But any move on abortion is likely to trigger renewed opposition from charities and women’s groups who warn it could lead to a cross-border trade in termination.

Campaigners had also warned that transferring the power from Westminster could lead to tougher laws in Scotland.

Any attempt to amend the Scotland Bill on extra powers in the House of Lords will also prove controversial.

The SNP has also warned that Scots would be outraged if changes were agreed in the unelected Upper chamber.

Abortion was one of the most explosive issues considered during the Smith Commission negotiations on further powers for Scotland, set up in the wake of the independence referendum result.

The cross-party talks almost collapsed at one point after abortion became a "red line" for Labour.

In the end the Smith agreement said that "further serious consideration should be given to its devolution and a process should be established immediately to consider the matter further".

Earlier this month Mr Mundell said that there was “no constitutional reason why abortion should not be devolved”.

The SNP and Conservative governments are due to hold discussions on the issue this summer.

Mr Mundell said that he hoped to have “something to say in agreement” with Scottish ministers when the Scotland Bill is debated again at Westminster.

Lord Purvis, the Lib Dem peer, said he intended to press the issue in the Lords if others diid not.

“It's surprised me that this hasn't been an issue," he said. "The SNP wanted to progress in Smith and haven't been pursuing it stronger since.”

An SNP spokesman said: "As the Smith Commission reported, the parties were 'strongly of the view' that responsibility for abortion should be devolved, given that health as a whole is devolved to the Scottish Government.”

But he added: "We have no proposals to change the existing legal position on the time limit for abortion."

However, Labour MSP Jackie Baillie, said: " Women's organisations, trade unions and human rights groups are clear that devolving abortion law could put a woman's right to choose at risk. Abortion law should be based on evidence, not lines on a map.”

The Scottish Government quietly dropped a demand for new powers over abortion earlier this year, saying that it was concentrating on other priorities instead.

But at the start of the summer the party’s MPs backed a move to devolve the powers to the Scottish Parliament tabled three pro-life MPs from other parties.

A SNP source said at the time that the party was “in the more powers business".

But there have been warnings from organisations including Amnesty International, the Human Rights Consortium Scotland and Scottish Women's Aid, who all signed a statement to MPs raising fears that devolution of abortion could lead to different laws north of the border.

It said: "Our concern is that this strategy of hasty devolution is being used in order to argue for regressive measures and in turn, a differential and discriminatory impact on women and girls in Scotland. Women across the UK have fought for women's bodies to be their own, and to this day, fight opposition to a women's right to choose.

"We do not wish this amendment to open the doors to those who seek to undermine this right."