Talks aimed at resolving the Southern Railway drivers' dispute are being held at the conciliation service Acas.
It follows a day of misery for thousands of Southern Rail passengers after drivers walked out in a row over the role of guards on the service.
All of Southern's 2,242 weekday services were cancelled, causing the worst disruption for more than 20 years.
Charles Horton, CEO of Govia Thameslink Railway, which runs Southern welcomed news of that talks would go ahead.
Both sides have engaged in a bitter war of words over who is to blame, with the unions and rail bosses blaming each other for allowing the strike to go ahead.
Colin Stanbridge, chief executive of London Chamber of Commerce and Industry, a business support organisation that represents thousands of companies, said the strikes were highly damaging to the economy, because many members of staff have arrived late or have not been able to get in to work at all.
Many passengers took to social media to vent their fury, including Jim Boyden, a management consultant, from Shoreham.
The 38-year-old shared a photo of his one-year-old son Zac, and wrote an emotional tweet to Southern about missing his bedtime story.
Managers at Southern Rail urged the unions to return to work, claiming that the strike was not the solution.
Angie Doll, Operations Manager, spoke to ITV News earlier.
But Mick Whelan, General Secretary of the ASLEF union, representing train drivers was forthright in his defence of the strike.
The current strike action is due to last for another two days, with more action planned later this month and into January, unless an agreement can be reached.
Transport Secretary Chris Grayling has refused to rule out taking action to prevent future stoppages.