Article 52 of the Contract Law is invalid under any of the following circumstances:

(1) One party enters into a contract by means of fraud or coercion, which harms the interests of the state;

(2) Malicious collusion that harms the interests of the state, the collective or a third party;

(3) Covering up illegal purposes in a legal form;

(4) damaging the public interest;

(5) Violating the mandatory provisions of laws and administrative regulations.