Updated: 9:36 p.m.

The House will formally pay tribute Wednesday to the victims of Saturday’s attempted assassination of Rep. Gabrielle Giffords, who remains in critical condition in a Tucson, Ariz., hospital.

President Barack Obama is scheduled to participate in a memorial service for the Arizona Democrat and the 19 other victims at the University of Arizona in Tucson on Wednesday evening. House Minority Leader Nancy Pelosi (D-Calif.) will travel with him to attend the tribute.

Giffords, 40, was seriously injured when authorities say 22-year-old Jared Loughner opened fire on a “Congress on Your Corner” event the lawmaker was hosting in Tucson on Saturday. Six people died, including federal Judge John Roll and Giffords’ outreach director, Gabe Zimmerman.

Doctors at the University Medical Center in Tucson announced Tuesday that Giffords is now able to breath on her own and that she has suffered only minimal swelling in her brain, two key indicators that her condition is improving.

But UMC’s chief of neurosurgery cautioned that the timeline for her recovery remains unclear. “She’s going to take her recovery at her own pace,”  Dr. Michael Lemole said.

Shortly after 10 a.m. Wednesday, Speaker John Boehner (R-Ohio) is expected to formally call up a resolution condemning the attack and naming all 20 victims, including the six people killed: Roll, Zimmerman, 9-year-old Christina Taylor Green, Dorothy Morris, Phyllis Schneck and Dorwan Stoddard.

The resolution condemns the attacks in the “strongest possible terms,” while reaffirming “the bedrock principle of American democracy and representative government, which is memorialized in the First Amendment of the Constitution and which Representative Gabrielle Giffords herself read in the Hall of the House of Representatives on January 6, 2011.”

Lawmakers are likely to spend much of the day honoring Giffords and the other victims in floor speeches. Boehner, Minority Leader Nancy Pelosi (D-Calif.), Majority Leader Eric Cantor (R-Va.) and Minority Whip Steny Hoyer (D-Md.) are expected to give speeches.

Members and their spouses will also attend a prayer service for the victims Wednesday, and the House will have condolence books available for lawmakers to sign.

Obama will take part in the service at the university’s McKale Center “to support and remember victims of the mass shooting in Tucson, and to lift the spirits of those who have been personally affected by this tragedy,” according to the university’s website. First lady Michelle Obama will also attend the “Together We Thrive: Tucson and America” event, which is free and open to the public.

During the House’s pro forma session Tuesday, the chamber’s chaplain prayed for the shooting victims. The Rev. Daniel Coughlin asked that God “touch with healing power those who are sick, grieving or wounded. Grant peace to those who have died suddenly and consoling love to all who mourn.”

With funeral services for the six victims being planned in Arizona, state legislators have begun to try to head off protests planned by the Westboro Baptist Church. The controversial church has made a name for itself by holding protests at military funerals and other events to draw attention to its beliefs. The Arizona legislature on Tuesday passed a bill creating a 300-foot buffer between the funerals and any protests, and Gov. Jan Brewer (R) signed it into law that evening.