The world-famous engineering marvel will be drained of water for three months if the blueprint is backed by Harborough District Council.
Oak gates will be replaced on five of the 10 locks, brickwork in the lock chambers will be repaired and new lock ladders installed.
The massive Canal and River Trust operation is poised to begin on the Grand Union Canal attraction in January and be completed by March.
Built between 1814 and 1900, Foxton Locks is home to two fantastic feats of engineering.
As well as the longest and steepest staircase locks in the UK, the site also boasts the inclined plane, a magnificent piece of Victorian engineering.
More than 4000 boats travel through the flight of locks every year and about 300,000 visitors flock to enjoy this unique canal landmark.