PRIME Minister David Cameron called blacklisting unacceptable as his Government said it had not seen evidence that would require a probe into the practice.
His comments came after allegations that members of the security forces and police were involved in drawing up lists that locked hundreds of workers out of jobs on construction sites.
Labour challenged the UK and Scottish Government to ensure blacklisting did not take place on any of their major projects. The party has warned the practice may still be taking place.
Downing Street said it had not seen evidence "that would require an inquiry".
Mr Cameron's spokesman said the Prime Minister would encourage anyone with evidence to take it to the Information Commissioner.
MPs have heard evidence some workers were targeted over union affiliations, or for being members of the Labour party. Union Unite has called for an inquiry.
Labour MP Ian Lavery said blacklisting "destroyed the lives of many innocent people".
Many have no idea they were included on a list compiled by a group called the Consulting Association, found when the Information Commissioner's Office (ICO) raided it in 2009.
Shadow Business Secretary Chuka Umunna said: "There are sufficient questions to justify the Government carrying out a full investigation into the extent blacklisting took place and may still be taking place, at the very least on public sector projects.
"The Government should then set out what practical steps may be needed to stop blacklisting and blacklisting checks happening on public projects."
Kate Devlin
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article