Chellaston lines, formally.
Yes one of them was. The other line headed towards Derby which now partly forms the freight branch to Rolls Royce.
Aren't some of the warehouses already connected? In other words the warehouses used by M & S?
Just looking at Bing aerial there appears to be a rail loading pad west of the big warehouse, but I can't say if it's used or just something they had to provide to get planning approval (meaning that at least it could be used if a potential tenant wanted to).
A landlord has no power to require tenants to use rail, and generally speaking a local planning authority can't require this either. By making planning permission conditional on providing a rail connection, at least that connection is there in the future and if there are enough around the country there is more chance of being able to set up a freight flow between two of them.
It was in the planning conditions, keeping as many HGVs off the roads as possible by using railfreight was the aim....planning passes, warehouse built, BUT M&S never had any intention of using rail
