(NewsNation) — Kroger CEO Rodney McMullen is testifying before a Senate antitrust panel to defend the chain’s proposed merger with Albertsons.

Albertsons CEO Vivek Sankaran is also testifying, along with experts in economics and antitrust regulation.

The Federal Trade Commission must approve the proposed merger of the country’s two biggest grocery chains.

In October, Kroger announced plans to purchase Albertsons for $24.6 billion. The two companies encompass a number of other grocery chains, with Kroger owning Ralphs and Harris Teeter, while Albertsons includes Safeway, Tom Thumb, Acme and Jewel-Osco.

In an effort to appease regulators, the chains said they would sell up to 375 stores to create competition.

It’s a move similar to one that happened when Albertsons acquired Safeway in 2014, when 168 stores were sold so Albertsons wouldn’t be able to dominate market share in regions where both brands existed.

The small grocery chain that acquired the majority of those stores was unable to handle the expansion and filed for bankruptcy. It also wound up selling some of those stores back to Albertsons.

Current FTC Chairwoman Lina Khan has criticized the way the agency handled that deal.

Union leaders are planning to hold a press conference asking lawmakers to stop the merger.

The proposed merger comes as inflation has caused grocery costs to rise, putting a strain on people’s budgets.

Lawmakers are expected to ask how the merger will impact customers and what the company would do to help lower costs and improve wages after the deal.