THE Scottish Labour leadership contest has been rocked by claims of new members joining the party after providing the same email addresses and mobile phone numbers.

Party sources said a sizeable number of new recruits who had signed up in recent weeks provided identical personal details in their applications.

The insiders fear that if multiple members are linked to a single email address it raises the prospect of an individual casting someone else’s vote in the electronic ballot.

At least two secretaries of Constituency Labour Parties (CLPs) that nominated left-winger Richard Leonard for the leadership yesterday raised concerns with Scottish Labour about email addresses.

A spokesperson for the Leonard campaign said if complaints had been made then "we expect these will be dealt with through Scottish Labour Party's procedures."

A spokesperson for the campaign of Anas Sarwar, who is going head-to-head with Leonard, said: “It’s incredibly encouraging that people across Scotland have joined the Labour Party and we are confident that many have been enthused to do so by Anas’s positive campaign and by a belief that he can be the next Labour First Minister."

Leonard and Sarwar, both of whom are new MSPs, are in the middle of a bitter contest to become Labour’s ninth leader in the devolution era.

The internal election has also been used as a recruitment drive and the party's governing Executive allowed individuals to join up until Monday this week. New members and supporters can vote in the contest.

At the weekend, a Labour source told the Sunday Herald that, of around 1600 sign-ups, around 1200 were Asian members. It was claimed the members had been signed up to “edge it” for Sarwar.

The Herald can now reveal that the application process put in place by Labour is under the spotlight. Under the system, new members were asked to provide a name and phone number, as well as postal and email addresses, but signatures were not required.

Party sources have said that clusters of new members have come from within individual households, which in itself is not unusual as extended families can often live together.

However, in some cases, the same mobile phone number has been provided for all or many of the new members under one roof.

A senior party source said having one mobile for five or six people in one house made it “hard for Labour to contact these new members for verification purposes”.

It is also understood that some of the new members in multi-resident households put down the same email address.

Sharing an email with a relative is not unheard of, but the scale of the practice is causing concern internally. Family members who submitted the same email address will have their electronic ballots tied to the same account.

However, it is understood that where more than three people are signed up for a vote at one email address, Labour will send them individual postal ballots.

Where three people use the same email address, there will be three separate personalised emails, with different security codes.

However, a party source said the procedure for cases where three people use an email address was "unsatisfactory".

There is no suggestion of wrongdoing by any candidate, but the revelations have raised further questions about Labour’s decision to allow new members to join during the contest and the procedures for checking the recruits.

A verification panel, chaired by interim party leader Alex Rowley, has been set up to scrutinise the sign-ups.

A Scottish Labour spokesperson said: "Every day new members are joining Labour as they are inspired by our vision for a country that works for the many, not the few. The party has a robust process in place to ensure verification of new members and registered supporters."