Morrisons has instructed DWF to defend a group claim by 2,000 of its employees over a massive breach of data security.

The leak by a former staff member, Andrew Skelton, led to salary, bank account and National Insurance details for 100,000 of its staff being published online last March.

Skelton was jailed for eight years in July for the breach.

The claimants have turned to JMW Solicitors partner Nick McAleenan. The claim, due to be filed in the next two weeks, will allege Morrisons was ultimately responsible for the breaches of privacy and data protection laws.

McAleenan said the firm was also recruiting further Morrisons’ staff to join the action.

The case is expected to be the biggest ever claim in relation to a mass breach of data to hit the London High Courts.

DWF partner Andrew Harris has instructed 11KBW junior Anya Proops.

McAleenan has instructed Jonathan Barnes of 5RB Chambers.

Morrisons launched its first ever legal panel in 2013 with DWF, Allen & Overy, Ashurst, DAC Beachcroft and Eversheds among the roster of 15 firms appointed. General counsel Mark Amsden at the same time pledged to double the supermarket’s in-house team to eight lawyers by the end of that year.

The legal lineup

For the claimants, Morrisons’ employees

5RB Chambers’ Jonathan Barnes, instructed by JMW partner Nick McAleenan

For the defendant, Morrisons

11KBW’s Anya Proops, instructed by DWF partner Andrew Harris