It’s wartime between General Motors and Fiat Chrysler Automobiles after the former filed a lawsuit against the latter and several of its former executives, with GM accusing its competitor of corrupting labor talks over the past decade. GM said that the scheme cost the company billion of dollars with the lawsuit also claiming that the late FCA boss Sergio Marchionne conspired with the UAW to “effectively take over GM through a merger.”

Shortly after GM went public with its action to file a racketeering lawsuit, FCA issued a short statement to defend itself, calling it a maneuver by its Detroit rival meant to disrupt the merger with PSA and UAW negotiations

“We are astonished by this filing, both its content and its timing”, said FCA. “We can only assume this was intended to disrupt our proposed merger with PSA as well as our ongoing negotiations with the UAW. We intend to vigorously defend against this meritless lawsuit and pursue all legal remedies in response to it.”

Read: Official: FCA And PSA Agree To Merge, Create The World’s Fourth Largest OEM

At the end of October, the PSA Group and FCA stepped forward confirming merger negotiations, which would create the world’s fourth largest OEM, after the Volkswagen Group, Renault-Nissan-Mitsubishi Alliance and Toyota.

The partnership would benefit both companies as they could share production costs by giving each other access to the outgoing platforms and technologies. In the near future, they could co-develop new car platforms, which would be used in the next generations of their vehicles.

The numbers game would obviously be on their side as well, as between them, they managed to shift 8.7 million vehicles worldwide last year. General Motors came about 300,000 cars short, but the podium was dominated by the Volkswagen Group, with 10.8 million units, closely followed by the Renault-Nissan-Mitsubishi Alliance and Toyota Motor Corp.