SNP membership has grown since the launch of the Alba Party, The National can reveal.

Media coverage since the Friday launch of Alex Salmond’s new party – which seeks a “supermajority” for independence in the Scottish Parliament – has questioned what the move will mean for Nicola Sturgeon’s organisation as a raft of high profile members including MPs Kenny MacAskill and Neale Hanvey announced their defection.

Today The National can reveal the SNP’s membership has increased since Friday.

A senior party source told this newspaper that fewer than 100 people had cancelled their subs.

Meanwhile, more than 300 new members have signed up.

The source said: “You don’t want to lose any members, but there is always some variation. The number of people leaving is negligible and we have put on a lot more than that.”

The news will be a boon to Sturgeon’s party in the run up to a Holyrood contest which will see the SNP’s two most recent leaders face each other at the polls. Launching Alba, Salmond insisted his party will work with the SNP, not against it, and is contesting only list seats. It has sent a “both votes Yes” message to voters, urging them to back the SNP for their constituency and Alba for their region.

READ MORE: SNP set for a clear Holyrood majority as new polling puts Yes ahead in indyref2

Yesterday it emerged that the names of 4000 people said to have signed up to Alba events had become visible to web users. The Herald on Sunday reported that this was a “glitch”. However, in a message to members, Alba said it was the victim of a “potential hack” which has been referred to the Information Commissioner’s Office. Assuring members that they “can be confident that the site is now secure”, the party’s Kirk J Torrance – a former SNP strategist – said officials learned of the breach at 10.30am on Saturday, adding: “No personal information beyond the names has been hacked.”

He went on: “We will not allow this type of black arts activity to deflect from our entirely positive campaign to gain a supermajority for independence in the Scottish Parliament.”

The names released in the leak include those of some councillors and SNP national executive committee (NEC) members who have now witched to Alba.

The data, which should not have been released, showed the “recruiter ID” of people who have registered for Alba events. However, one SNP member whose name was included told The National she had not joined Alba and instead registered “for a nosey”.

NEC member Brian Lawson, who was named in the Herald on Sunday article, said he had visited the site but had not signed up for anything and has “no plans to”. Lawson, a former Renfrewshire Council leader, told this newspaper he was not contacted by the Herald on Sunday prior to publication. He said: “As far as I’m concerned, anyone can sign up under any name. I went to the website to read what they were saying, but there was nothing to read. I certainly didn’t type my name into any form.”

The Information Commissioner said it will “be closely monitoring how personal data is used during political campaigning and making sure that all parties and campaigns are aware of their responsibilities under data protection and direct marketing laws”.