Train operating companies are set to make a new offer to striking rail workers this week, after receiving a revised mandate from the government.
The Rail Delivery Group (RDG), representing the firms, needs government backing for any deal.
RDG chair Steve Montgomery said he had received a revised mandate, which would be “used” in talks with the TSSA and RMT unions on Thursday.
Details could not be shared for confidentiality reasons, he said.
Train operators and unions are at loggerheads over pay and conditions.
Last week strikes led to widespread service cancellations across the network and union leaders warned industrial action could continue for months. But currently no further strikes are scheduled.