The UK government has been warned that train drivers' union Aslef would "never back down" on safety. This comes after a major breakthrough in the long-running and bitter Southern Rail dispute on Thursday (2 February 2017).

"Our message is quite simple: on safety, we will never back down," Aslef general secretary Mick Whelan told IBTimes UK.

"We should refer to the Eighties, because if you put people in a situation where they can't articulate their voice or their views, they will wildcat [strike].

"Of course, if they do wildcat because of 'Maggie's Laws', we will not be part of the solution, then who do you deal with?"

The general secretary, speaking after a fortnight of "incredibly intense" negotiations at the Trades Union Congress' London headquarters, also said the peace deal between Southern Rail operator GTR and his union would address some safety concerns.

"We believe what we have done has made it safer. Not having the guarantee of a second person on the train in 21st-century Britain – I don't believe that late at night, early in the morning, lone working meets the needs of the travelling public," Whelan said.

The dispute around driver-only-operations (DOO) and the future role of rail guards on the franchise has led to travel misery for the 300,000 or so commuters who use Southern.

Whelan said he had a "great deal of empathy and sympathy" for those affected by his unions' walkouts, but he argued that the industrial action has acted as "catalyst to assist both parties to move in certain areas".

Aslef is now balloting its Southern members on the deal, with the result of the referendum to be announced on 16 February.

The details of the arrangement have not been disclosed to the public because Aslef and Southern want the drivers to see the deal first. But Whelan confirmed that there is no pay or conditions offer from Southern. "This isn't a template for other companies. I want to make it quite clear that we've gone out of our way to find a resolution in relation to a particular industrial dispute," he added.

Nick Brown, the chief operating officer of GTR, also told IBTimes UK that the issue of remuneration was not raised during the talks. "I'm not going to go into all of the details, but there's been quite a bit of give and take in terms of where we come from and where Aslef have come from," he added.

Brown also admitted that it had been "awful" for Southern passengers. "We're very sorry, genuinely, for the inconvenience and disruption that they have been put through," Whelan said.

Southern remains in dispute with the RMT Union, which represents conductors on the franchise. Brown stressed that his door remains open for peace talks, while RMT chief Mick Cash issued a statement in response.

"The RMT understands that central to the agreement with Aslef is a guarantee of a second person ‎on the train," he said. "We also understand that the implementation of that aspect of the agreement is subject to further discussions and negotiations with RMT around the safety competencies of that second member of staff.

"It is now essential that we open up urgent ‎discussions with GTR around this core issue of the second safety-critical staff member, and the details of their future role, that will allow us all to move forwards. RMT is available for those talks with immediate effect. "