with might and main
• with all one's strength or power.
Similar:
with all one's strength,
with everything one has got,
to the best of one's ability,
as hard as one can,
as hard as possible,
all out,
with maximum force,
(with) full force,
full blast,
with all the stops out,
forcefully,
powerfully,
strongly,
vigorously,
enthusiastically,
hammer and tongs,
like crazy,
like mad,
