1
general::
Difficult work or progress, as in This bill faces tough sledding in the legislature. This idiom transfers the route on which a sled can travel to other kinds of progress toward a goal. It was first recorded as hard sledding in 1839. For the antonym, see EASY SLEDDING.
American Heritage Idioms
2
general::
Phrase(s): tough sledding
Go to hard sledding.
McGrawhill's American Idioms And Phrasal Verbs