Verb to make something more strict
Solution 1:
The regulator _______ the rules governing party A's promotion practices.
The word you're looking for is tighten (up).
Tighten (verb): If someone in authority tightens a rule, a policy, or a system, they make it stricter or more efficient.
Example: The Government plans to tighten the economic sanctions currently in place.
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You could also say 'strengthen'.
Strengthen (verb): If a government strengthens laws or measures or if they strengthen, they are made more severe.
Example: I am also looking urgently at how we can strengthen the law.
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