Network Rail has said two houses at the site of the Baildon landslip will have to be demolished after being deemed at risk of collapse.
Train services between Bradford Forster Square and Ilkley have been suspended since February, with Northern now saying the line will remain closed until further notice.
Network Rail and contractor teams have been on site for almost two months, with specialist road rail vehicles and other equipment utilised to remove more than 1,800 tonnes of earth to stabilise the land.
A Network Rail spokesperson said: “Passengers who rely on this line have been inconvenienced by its closure since 9 February, and for safety reasons we have been unable to make any meaningful progress on site for several weeks.
“We are obliged to do everything we can to reopen this vital rail link for passengers, school children and their families, stakeholders and the broader West Yorkshire economy.
“We have been in discussions with various third parties since this incident was first reported to us six weeks ago, but the complex nature of the site and the critical need to reopen the line means that regrettably, we now have no remaining options but to use our statutory powers to allow us to resume the repairs to this site which will allow trains to start running again.”
Network Rail has said it hopes now to have the line open by the end of June.