SCOTTISH Labour has been urged to investigate a mass sign-up of hundreds of new members in leadership candidate Anas Sarwar’s local constituency party.

The Secretary of the Glasgow Southside party has claimed that some new recruits who share the same mobile phone number are listed as living at different addresses.

The office bearer also claimed that a tranche of new members have given the same business email address. These matters have been raised as potential irregularities in the election process.

Separately, phone bank volunteers for left-wing leadership candidate Richard Leonard MSP have contacted new sign-ups across Scotland who deny joining the party, fuelling fears of “ghost members”.

A spokesman for the Leonard campaign said of the Southside claims: "Where there have been complaints then we expect these will be addressed in accordance with the Scottish Labour Party's procedures."

However, a spokesman for the Sarwar campaign 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.

"Jeremy Corbyn is among those to encourage people to join the party, and it is deeply disappointing if some are now launching a smear campaign against new members.”

An SNP spokesperson said: ''Labour's leadership race gets dirtier and nastier by the day.''

CATCH UP: Contest hit by row over new members joining with same email addresses

Leonard and Sarwar, an MSP on the right of the party, are vying to replace Kezia Dugdale as leader, but the race has descended into one of the most bitter contests in living memory.

Much of the rancour can be traced to the party’s decision to use the election as a recruitment tool by allowing individuals to join and get a vote.

Two primary routes have been used, both of which are legitimate: membership of the party; and signing up as a “supporter” through an affiliated organisation such as a trade union.

Leonard’s backers have favoured the union supporter route in the contest, while Sarwar backers have signed up a huge number of members across Scotland. The deadline passed last week.

It is understood that around 2000 new members may have joined Scottish Labour in the last few weeks, a substantial rise.

However, pro-Leonard constituency Labour parties (CLPs) have raised concerns about the large number of new members who share email addresses and mobiles.

A shared mobile for six or seven people is believed to make it harder to verify the individuals, while a shared email means multiple electronic ballots being accessed by the same account.

The Sunday Herald can reveal a surge of members has been recorded in the Glasgow Southside CLP, which is Sarwar’s political base.

It is understood the local party had around 700 members last year, but hundreds more are said to have joined in recent weeks.

On Wednesday, the Secretary of the Glasgow Southside CLP emailed party general secretary Brian Roy and members of the Scottish Executive Committee (SEC) to outline his concerns.

He wrote that many of the new sign-ups have the same email and phone number and claimed that some email addresses appear four times or more on the full membership list, relating to around 120 members.

He claimed that some of the individuals with the same mobile number are listed at different addresses across the constituency.

The local official also put in writing a concern about fourteen people giving the same business email.

The office bearer added that, barring a few exceptions, all of the new members had joined since the contest started and called for an investigation by an SEC sub-committee.

However, a source close to the Sarwar camp said the Glasgow Southside CLP did not discuss these matters at its meeting last week, adding that the Secretary had acted alone.

There is no suggestion of wrongdoing by Sarwar, but the email from inside his own constituency party will likely strengthen calls for strong vetting.

A verification panel, under the chairmanship of pro-Leonard interim leader Alex Rowley, is considering the applications.

A party source said: "There is unavoidable evidence of a pattern of recruitment of new members in which many people share the same mobile phone number or email address, and - most worryingly - that there are people who do not know that they are members at all: ghost members in effect.

“It is an open secret in the party that this is happening and much tougher action is required to establish how and why. It isn't good to address the symptoms - there has to be action to establish the causes.”

On a national level, it is understood that volunteers on the Leonard campaign have contacted new members, only to be told by some of the sign-ups that they had not joined. Leonard’s campaign declined to comment.

A Scottish Labour spokesperson said: "The party has a robust process in place to ensure verification of new members and registered supporters."