EQUALITY campaigners have reacted angrily to a government proposal to scrap civil partnerships and rule out allowing heterosexual couples to enter into the unions in Scotland.

Ministers have launched a consultation asking whether civil partnerships, which were introduced less than a decade ago and are only available to same-sex couples, should remain as they are or be phased out.

It has welcomed views on extending the right to everybody, but the SNP Government made it clear that it is "not persuaded" by the option, citing possible cost implications and the likely low demand.

Sources said that looking again at civil partnerships, including possibly ruling that no new unions could be entered into in future, was a "logical step" following the legalisation of gay marriage last year.

However, one leading equality campaign group has expressed "surprise and disappointment" that extending civil partnerships to everybody had already been dismissed, arguing that true equality meant it should be available to all.

Tim Hopkins, Director of the Equality Network, said: "We know that a significant minority of mixed-sex and same-sex couples would prefer a civil partnership to a marriage, and at the moment only same-sex couples have that option."

The charity said its own research showed that more than seven in ten people believe civil partnerships should be available to heterosexual couples. It believes there is "clear demand" for civil partnership to be extended, with some opposed to the traditions and religious connotations of marriage.

The Scottish Government released figures that showed that since the introduction of gay marriage last December, demand for civil partnerships - which were introduced in 2005 and confer the same legal rights as marriage - has plummeted.

Between April and June this year, there were eight civil partnerships, 121 fewer than during the same three-month period last year. Meanwhile, there were 427 same-sex marriages, more than half of which were among couples who have previously had a civil partnership.

However, in countries such as Holland where heterosexual couples are allowed civil partnerships, research shows that as many as 10 per cent choose the option. In England, a mixed-sex couple who described marriage as patriarchal launched a legal challenge last year arguing that they should not be denied a civil partnership due to their sexuality.

Patrick Harvie, co-convenor of the Scottish Greens, said he had been arguing for more than a decade that civil partnerships should be open to everybody on equal terms.

The MSP added: "With the overwhelming support of Parliament for equal marriage there is surely now no coherent argument against equal civil partnership too. It may only be of interest to small numbers, at least initially, but since the institution already exists, and abolishing it would be unacceptable, it should be opened to mixed-sex couples."

But The Very Rev Kelvin Holdsworth, Provost of St Mary's Cathedral in Glasgow and a prominent campaigner for LGBT rights, said opening up civil partnerships would risk undermining marriage which he said was now the "gold standard" of committed relationships and open to everyone.

He added: "Those who are campaigning for civil partnerships to be extended to straight couples need to remember that the civil partnership system was born in inequality and that inequality is remembered negatively by many of us. My own view is that there's no need to change the law in this way.

"Those who argue that marriage carries negative connotations which they personally disagree with seem not to have understood the huge changes that have been taking place to marriage itself over the years. It is now available to straight and gay alike, just as it is administered in both secular and religious contexts. Marriage has been changing and has changed enough for there to be no need to extend civil partnerships to anyone else."

The Scottish Government said existing civil partnerships would still be recognised, with no obligation to convert to a marriage, even if they are phased out. Any changes to the law will be voted on by the next Holyrood parliament following May's elections.

Marco Biagi, the minister for local government and community empowerment, said: "This Government is immensely proud of introducing same sex marriage, which was a milestone in achieving equality in Scotland.

"During the Parliamentary passage of the Marriage and Civil Partnership (Scotland) Act 2014 we said we would consider the future of civil partnerships, which is what our consultation now seeks to do.

"We remain open to hearing all views on the options set out in the consultation but, after careful consideration of this issue, we are not persuaded of the case for the establishment of opposite sex civil partnership in Scotland."