By Anna Moloney Train company bosses will be working with a “revised mandate” which could include a better pay offer as they enter the latest round of talks with unions, the transport secretary has suggested. Mark Harper said train operators have been given his “permission” to make a new offer to the trade unions. The minister claimed he had made sure a “better deal” on pay was available to rail workers, as he continued to make the case for changing operating conditions on the railways. Harper’s claims come as train operating companies, Network Rail and the trade unions are set to start the ne…