Colorado grocery workers joined labor advocates and elected officials outside Denver city hall on Monday to rally against a proposed $24.6 billion merger between the nation’s two largest supermarket chains,

The event lined up with the start of a trial between the state of Colorado and grocery giants Kroger and Albertsons, which are pushing to merge.

For the third time in just over a month, Kroger on Monday will face off with regulators over its embattled proposed $25 billion merger with Albertsons – this time against Colorado Attorney General Phil Weiser's office in a state lawsuit being tried in Denver District Court.