hold someone to ransom
hold (one) to ransom
To demand something or some action from someone by threatening them with a harmful consequence if they do not comply. Threatening us with a fine if we don't participate in the survey is a bit like holding us to ransom, isn't it?
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
hold someone to ransomBRITISH
COMMON If one person holds another to ransom, the first person uses their power or influence to force the second to do something they do not want to do. But who are the powerful men at the Bundesbank who have the power to hold Europe to ransom? Giorgio Armani, the fashion guru, refused to be held to ransom by greedy catwalk supermodels.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012