An inquiry into allegations of vote-rigging in Falkirk could hang over Labour for months, even running into to the party's annual conference, it has emerged.
Although police have said they will not launch a probe, the Information Commissioner's Office (ICO) is conducting an inquiry into whether data protection laws were broken, an offence that can carry a fine of £500,000.
The investigation is expected to last "months, not weeks", according to a spokesman for the ICO.
Labour is carrying out its own internal disciplinary procedures alongside the ICO inquiry.
The selection of Labour's 2015 General Election candidate in Falkirk has been shelved until the disciplinary process has run its course.
Party leader Ed Miliband said earlier this month that an internal Labour report had shown "people were being signed up as members of the Labour Party without their knowledge".
He appeared to successfully draw a temporary line under the row by taking on the Unite union – which is at the centre of the allegations and was backing Falkirk candidate Karie Murphy – and announcing a series of reforms designed to change Labour's relationship with the trade union movement.
However, his gamble, which has already led to claims Labour will lose millions in union funding, is expected to create tensions within the party.
Mr Miliband has attempted to kick those arguments down the line by emulating Tony Blair's Clause 4 moment and announcing he will hold a "special conference" on the issue early next year.
But senior party sources say they expect the topic of the reforms will be a major battleground at this year's annual conference in Brighton in September. Many within Labour already believe the week-long event will be crucial to Mr Miliband's campaign to win over the public.
The Labour leader silenced many of the naysayers within his own party with a powerful conference speech last year in which he made the surprise move of adopting the former Conservative slogan of "One Nation".
But in recent months Labour has suffered a slump in the polls and seen its lead over the Conservatives narrow.
A spokesman for the ICO said he could not say when its inquiry would conclude, but added that in general investigations by the office took months rather than weeks.
The probe began a few weeks ago, before the Conservative party referred the Falkirk allegations for investigation.
A source said a proactive decision had been made to look at the claims.
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