plug away

plug away (third-person singular simple present plugs away, present participle plugging away, simple past and past participle plugged away)

1. (informal) To persist or continue, as with an effort.

   He kept plugging away at the work until it was done.

   • 2020 May 20, John Crosse, “Soon to be gone... but never forgotten”, in Rail, page 63, photo caption:

     The end is nigh (or at least it was supposed to be), but the Pacers in northern England kept plugging away providing a service while awaiting the much-delayed arrival of their replacements.

• chip away