MSPs have rejected plans to introduce a non-binary gender option to the next census in Scotland when it takes place in 2021. 

The Members of the Parliament's Culture Committee said the Scottish Government consultation into plans to allow people to choose their gender in the next census had 'serious deficiencies', among them a failure to give sufficient consideration to the views of women's groups. 

A report from the committee said that the consultation appeared to have involved only 'very small numbers of people' drawn overwhelmingly from the LGBT community, the Scottish Herald newspaper reports.

The committee recommended that the census continue to ask people whether they are male or female, arguing that a non-binary option would create 'confusion' and compromise data drawn from the census on sex. 

The committee's convener Joan McAlpine MSP said: 'The purpose of the census is to accurately reflect our society and gather vital information for the provision of public services and the development of policy.

'However, there has been a serious lack of consultation, with a range of women's groups, which has led to legislation being published which is not fit for purpose.

'Had a proper, robust consultation been undertaken in the first place a lot of these issues could have been avoided.'

The findings were welcomed by Lucy Hunter Blackburn of the Edinburgh-based policy analysis group, Murray Blackburn Mackenzie.  Writing in the Scottish Herald, she said it was important that the Scottish Government not conflate sex with gender identity and gather data separately on both. 

She said accurate data on sex was needed to inform policy and spending in areas such as health, education and sex discrimination, which is prohibited under the Equality Act 2010. 

'If the question on "sex" becomes in practice a question on gender identity, we cannot know how this would affect the data,' she said.

'Small differences at the level of the whole population could become significant for particular sub-groups, perhaps most obviously by age.

'Losing reliable data on sex will make it harder to tell how well hard-won protections set out in the Equality Act are being upheld across the population.

'The census is a once-in-a-decade opportunity: getting the data right matters. Irrespective of wider societal change, sex-based discrimination remains stubbornly commonplace.

'As such, the approach recommended by the committee, which purposefully avoids conflating sex and gender identity, is both pragmatic and welcome.' 

A non-binary option was recently rejected by the Office for National Statistics for the next census in England and Wales, although it supported the introduction of a voluntary question on gender identity for over-16s. 

A spokesperson for the National Records of Scotland, which had supported a non-binary option, said: 'The intention behind the Census Bill has never been to conflate sex and gender identity and we will consider the issues raised in the report.'