If the lawyer representing the plaintiff does not close the case, he will terminate the agency relationship with the plaintiff and bring a lawsuit against the plaintiff on behalf of the defendant. You can't. Because lawyers already know the plaintiff very well, it is unethical to represent the defendant in turn. You can report it to the justice bureau.
Legal basis: Article 27 of the Measures for Punishment of Illegal Acts of Lawyers and Law Firms is an illegal act of a law firm "accepting cases with conflicts of interest in violation of regulations" as stipulated in Item 5 of Article 50 of the Lawyers Law, and it is under any of the following circumstances:
(1) Entrusting our lawyers to act as agents of the plaintiff and defendant in the same litigation case, or as defenders of the defendant and agents of the victims in the same criminal case;
(2) Failing to examine the conflicts of interest in the entrusted matters in accordance with the provisions, and at the same time or successively appointing lawyers as agents or providing relevant legal services for the parties involved in non-litigation legal affairs with conflicts of interest;
(three) knowing that lawyers and their close relatives have conflicts of interest with the entrusted matters, they still entrust lawyers as agents, defenders or provide relevant legal services;
(4) conniving at or letting our lawyers commit the illegal acts stipulated in Article 7 of these Measures.