clampdown
noun [ C, usually singular ]
uk/ˈklæmpdaʊn/ usan action by a government or other authority to stop or control an illegal or unacceptable activity:
In the wake of the attacks, a temporary security clampdown at border crossings has created major traffic jams.
a clampdown on sth In a clampdown on tax fraud, more than 400,000 companies and public servants were audited last year.