Train operator Thameslink said that no Brighton trains would be running north of Luton while recovery work is carried out after the crash on Friday (19 June).
One train driver died and more than 100 people were treated in hospital as a result of the crash involving two trains in the Bedford area.
And the British Transport Police (BTP) said that 53 people remained in hospital, eight of them in a critical condition.
Thameslink said: “Following the emergency services responding to an incident involving a collision between two East Midlands Railway trains in the Bedford area on Friday 19 June, the railway is expected to remain closed between Luton and Bedford until at least the end of the day on Friday 26 June.
“A complex recovery operation has begun to remove the damaged trains from the railway before Network Rail engineers assess any damage and complete necessary repairs.
“East Midlands Railway and Thameslink are advising that you only travel on this route if it is essential and to work from home where possible.”
