The Senate’s top two Democrats are slated to attend separate rallies Saturday organized by a major labor union and immigrant advocates as part of a “national day of action” aimed at pressing Congress to take up comprehensive immigration reform this year.

Senate Majority Leader Harry Reid (D-Nev.) will be joined at a Las Vegas rally by Rep. Luis Gutierrez (D-Ill.), according to Ali Jost, a spokeswoman for the Service Employees International Union, which is working with other immigration rights groups to organize events Saturday in Chicago, Las Vegas and Seattle.

Reid spokesman Jon Summers confirmed Friday that Reid, who faces a potentially tough re-election this year in a state where Hispanic voters’ influence is on the rise, would attend the rally and deliver remarks to participants.

The rallies come on the heels of vigils taking place across the country Friday outside regional Immigration and Customs Enforcement offices calling for an end to what protesters say are outrageous enforcement tactics associated with recent workplace raids.

Senate Majority Whip Dick Durbin (D-Ill.) will speak at the Chicago rally “about his hopes for comprehensive immigration reform” and his efforts to work with Sen. Charles Schumer (D-N.Y.) — who chairs the Judiciary subcommittee that handles immigration issues — as well as with Sen. Lindsey Graham (R-S.C.) and others “to get a bipartisan bill introduced and on the floor this year,” Durbin spokesman Joe Shoemaker said.

Gutierrez, an influential member of the Congressional Hispanic Caucus, is one of the most fierce advocates for comprehensive immigration reform. He, Speaker Nancy Pelosi (D-Calif.) and others have called for an end to the ICE raids.

Congressional action on immigration legislation before the November midterm elections is considered a long shot, but Reid has kept the issue on a list of possible agenda items for the Senate’s seven-week work period that begins next week and runs through Memorial Day.

The Senate would have to move first on any immigration bill, aides say, as part of an agreement between Reid and Pelosi, who is wary of subjecting House Democrats to potentially politically challenging votes without assurance of Senate action.