Lawyers from Quinn Emanuel Urquhart & Sullivan are fighting an attempt by their former client, Uber Technologies Inc., to disqualify the firm from pursuing antitrust claims against it by a former rival ride-hailing app.

Uber’s current lawyers at Gibson, Dunn & Crutcher filed a motion in February to disqualify Quinn Emanuel from representing SC Innovations Inc., the successor to the defunct Sidecar ride-sharing company. Uber contends that Quinn Emanuel represented it in at least 20 cases from 2012 to 2016 that delved into competition issues like the Sidecar case. The company also claimed that Quinn Emanuel lawyers had access to confidential Uber information.