Lesson for employers and unions from Southern Rail industrial action, says expert

Sarah Ashberry of Pinsent Masons, the law firm behind Out-Law.com, was commenting as Aslef, the train drivers' union, announced that it had reached a deal with network operator Govia Thameslink (GTR) over planned changes to the role of train guards. RMT, which represents the conductors as well as 12 drivers, described the deal as a "shocking betrayal" by Aslef.

Aslef members will now vote on the terms of the agreement, with the result due on 16 February, according to the BBC. RMT's dispute with GTR continues, although the company said it had invited the union for further face-to-face talks.

Ashberry, an industrial relations expert at Pinsent Masons, said that strike action by Aslef had been "absolutely devastating" to Southern Rail's service levels.

"RMT have been very vocal but their action could not actually halt the service in the same way as Aslef's," she said. "As ever, the lesson for employers is to plan ahead and check their own resilience to potential industrial action by specific groups of workers: identify the pressure points and those groups of workers who would be actually capable of stopping operations and build up contingency plans accordingly," she said.

However, Southern Rail commuters "should not celebrate yet" because the RMT was "capable of continuing to cause disruption and uncertainty to services, albeit not a total wipeout of services", she said.

"Commuters in other parts of the country should also be worried, because the RMT is continuing the campaign in relation to driver-only operation in other parts of the country, and Merseyrail is a new focus of dispute," she said.

The unions' dispute with Southern Rail began last year, in response to plans by GTR to replace train guards with 'on-board supervisors', and assign responsibility for opening and closing carriage doors to train drivers instead. So-called driver controlled operation (DCO) has been criticised by the unions as putting passenger safety at risk.

Although full details of the agreement between GTR and Aslef have not yet been published, Aslef general secretary Mick Whelan described it as a "significant step forward in addressing the safety concerns of Aslef members". However, RMT general secretary Mick Cash said that "passengers, including disabled passengers ... have lost the guarantee of a second member of staff on their trains".

The 2016 Trade Union Act will, once fully in force, create new hurdles for unions planning industrial action, particularly those operating in the transport sector and others deemed to be 'essential public services'. However, Ashberry said it was "doubtful" whether the new requirements would have made any difference in this particular case.

"Well-organised groups of employees like those involved in this dispute will surpass the new thresholds once they are introduced," she said.

The Act, which received Royal Assent last May, contains a new 50% voting turnout requirement for all ballots on proposed strike action, along with an additional threshold requiring 40% support for industrial action among non-ancillary staff regardless of turnout in relation to important public services, specified in regulations. The date from which these thresholds will apply has not yet been confirmed.