(Reuters) – Allianz (ETR:ALVG) and AXA on Thursday became the latest insurers to quit a global climate alliance that is holding crunch talks to decide its future in the face of growing political opposition in the United States.

Of the eight founding members of the Net-Zero Insurance Alliance (NZIA), which launched in 2021, at least five have now left and on Thursday the remaining members were holding a call to decide the group’s options, including whether or not to continue.

Allianz said in an emailed statement it had decided to leave the U.N.-convened NZIA, and said it would stick to its own climate goals. Axa, whose Group Chief Risk Officer Renaud Guidée has been chairing the alliance, followed shortly afterwards, saying it too would leave to “continue its individual sustainability journey”.

NZIA, which is trying to lower carbon emissions as part of the Glasgow Financial Alliance for Net Zero, has been buffeted by growing political opposition from some Republicans in the United States, which say the group could be violating antitrust laws.

This month 23 U.S. state Attorneys General told NZIA members that the group’s targets and requirements appeared to violate both federal and state antitrust laws. They gave insurers a month to respond in a May 15 letter seen by Reuters.

Swiss Re (OTC:SSREY) announced its exit on Monday, following Munich Re, Zurich Insurance and Hannover Re in leaving. All of these insurers have significant U.S. business or exposure.