ExxonMobil has launched an extraordinary lawsuit against two investment firms for the alleged offense of filing climate-focused shareholder proposals. The fossil fuel giant’s underlying goal: killing a federal regulatory effort that would make it easier for all U.S. shareholders to voice environmental and social concerns about the companies they own.

Critics say the company is also trying to intimidate shareholders from ever proposing such resolutions again in the future — under threat of being tied up in expensive litigation and incurring punitive financial penalties.

If successful, the Exxon lawsuit could set a legal precedent wrestling control away from regulators and cracking down on activist investors working to enact more climate-friendly policies.