at the expense of
US /æt ðə ɪkˈspens ʌv/
UK /æt ðə ɪkˈspens ʌv/

1.
a spese di, a discapito di
resulting in harm or damage to (someone or something else)
:
•
He pursued his career at the expense of his family life.
Ha perseguito la sua carriera a spese della sua vita familiare.
•
The company increased profits at the expense of environmental regulations.
L'azienda ha aumentato i profitti a spese delle normative ambientali.