A train company is holding talks with union officials in an attempt to avoid possible strike action.
The union has not ruled out strikes
Bosses at Midland Mainline are trying to resolve a pay dispute with members of the ASLEF union.
All rail services provided by the firm between the East Midlands and London were cancelled on Sunday while drivers attended union negotiations.
According to officials at the union, a deal had been agreed, but Midland Mainline pulled out.
Drivers have complained they are under extra pressure due to new services and disruption caused by work at St. Pancras station in London
Throughout Sunday, passengers arriving at Nottingham and Leicester faced a long journey to Grantham or Peterborough if they wanted to get to London.
Those at Derby were forced to travel via Birmingham.
Company bosses have apologised for the disruption and refunds are available for those who booked tickets.