Anti-Corbynites at the think tank Progress are persuading constituency branches to hand over the details of ex-members so they can recruit them to take out the leader.

At least, that’s the story doing the rounds of social media, along with the document apparently explaining exactly how to carry this manoeuvre out.

The online pro-Corbyn newspaper The Canary claimed: “Essentially, it is suggesting that Saving Labour supporters ask those who have access, to pass them the personal details of former Labour members.”

It argues Progress may have breached the Data Protection Act.

But the think tank’s director Richard Angell strongly denies any suggestion of impropriety. So what exactly do we know?

Progress is recruiting anti-Corbyn members

Progress is a centrist pressure group, and it has thrown its weight behind the challenge to Corbyn, particularly through a platform called Saving Labour. It's pushing hard before the deadline to register as a supporter and gain a vote.

Angell told The Staggers: "Labour needs a million strong party to take on the Tories at the next election. There is a 48 hour window before 5pm Wednesday and there is one strategy to save Labour.

“It's the Ronseal Strategy: register Labour supporters as Labour Registered Supporters." (For anyone not familiar with DIY, Ronseal is a brand of paint with the slogan “Does what it says on the tin”).

In other words, Labour’s moderates have learnt from Momentum. They know that many current members joined because of Corbyn, and they are trying to recruit in the opposite direction.

Progress wants to contact lapsed Labour members

The document which has been widely circulated online is a strategy for recruiting more moderate members.

It includes instructions on setting up street stalls and graphics to tweet on social media.

So far, so predictable.

What’s making online commentators jump is the following passage. The document recommends Corbyn’s opponents try to recruit those who left the party when he took over.

It continues: "With the support of your local CLP, this is something local members can do to recruit Labour supporters."

Then it has detailed instructions on how to access the data:

"There will be a specific account for each CLP and a link to the account in membership emails from the party - CLP officers with membership roles and the MP should have access - if not, call your regional party to sort it."

Corbynistas say this is breaching laws about data protection, and that former Labour Party members’ data is being used in a way they never intended. Progress says this is a misreading of the document in the first place.

So is Progress breaking any rules?

Tim Turner, an information specialist who is not a Corbyn supporter, said “there is a strong likelihood that the Data Protection Act is being breached”. He continued:

"If Saving Labour (or rogue individuals) are attempting to recruit Labour members back into Labour, then the processing of data is likely to be a breach of Data Protection’s fairness requirements."

But here’s the thing. Progress denies it is asking anyone to transfer any data. What it is telling Saving Labour campaigners to do is approach friendly constituency Labour party branches and ask them to target lapsed Labour supporters. And this is a perfectly legal question to ask.

The document itself makes no suggestion that campaigners should ask CLP to transfer any data to Saving Labour.

In short, it's up to the CLP. A pro-Corbyn CLP could just tell Saving Labour to bugger off and email lapsed members pro-Corbyn messages instead.

If someone in the CLP did hand over the database to an unauthorised “data controller” though, it could be a criminal offence.

What about Saving Labour?

The creation of Saving Labour, a platform to support the challenge to Corbyn, makes this whole data story more complicated.

If a Saving Labour campaigner recruits supporters at a street stall, then those people are now on a Saving Labour list.

But just as a CLP can’t give away its data, Saving Labour can’t hand its mailing list over either.

An information civil war

At the end of the day, both pro and anti-Corbyn factions are doing everything they can to pack the party full of their supporters. And it’s getting ugly.

Each CLP will have members on each side of the divide. But at the end of the day, if the leadership decides to throw its weight behind Corbyn or the challengers, that’s what will end up in your inbox.

So if you don't like what you're seeing, it might be time to adjust your spam filter.

Update: Labour responds to ICO complaints

The Labour Party has issued a statement responding to complaints about the last leadership election brought to its attention by the Information Commisioner's Office. It says it has been advised that:

If the Labour Party or its elected members intend to send marketing material to individuals (regardless of their membership status) it should ensure that consent is gained. A facility should be provided to allow the individual to consent to each method the Labour Party or its elected

members wish to contact them by. The implication of this direction is that candidates in internal Labour Party elections MUST NOT be given access to lists of existing registered and affiliated supporters which allow for unsolicited marketing messages to be sent by email or telephone. Indeed, there must be explicit consent given by each supporter to receiving marketing messages by each and every channel of communication.

As well as obeying the laws on data sharing outlined above, Labour must make it clear to members that they can opt out of mailing lists.

Most striking is the rule that elected representatives i.e. MPs cannot use the mailing list "save for normal membership procedures relating directly to their office". What that means, though, could be open to interpretation.

There should be a moratorium on any access to membership list by any office holder or elected representative save for normal membership procedures related directly to their office for the duration of this election. Any member using Labour Party membership data in an unauthorised way will be referred to the Office of the Information Commissioner and may be subject to disciplinary action.

But how will CLPs and MPs interpret this rule? If you get an email which you believe breaks the rules, you can send it to julia.rampen[at]newstatesman.com, and we can follow it up.