We have just been told by Moto, the company that runs Toddington services on the M1, that the slip road to the southbound services will remain closed until lunchtime on Saturday.
A lorry hit a raised curb on the way in on the slip road, cracking the fuel tank.
It left 600L (132 gallons) of fuel over the road all the way through the station before re-joining the motorway.
The contaminated area is extensive and a clean-up operation is under way.
The slip road has been closed to traffic all day, meaning no one can access the site from the motorway.