By Harriet McLeod
COLUMBIA, S.C. (Reuters) - South Carolina lawmakers plan to introduce a resolution on Tuesday to begin a debate on removing the Confederate flag from the State House grounds following the killings last week of nine African-American churchgoers allegedly by a white gunman.
Political leaders and civil rights organizations, including Reverend Al Sharpton's National Action Network, also plan to rally Tuesday in support of the measure on the steps of the State House in Columbia, about 120 miles (190 km) from Charleston, the site of Wednesday's shooting.
The battle flag of the pro-slavery Confederacy has become a lightning rod for the outrage that has gripped the state over the apparent racist motives behind the massacre. Federal authorities are investigating the attack as a hate crime by accused gunman Dylann Roof, 21, who posed with the flag in photos posted online.
Opponents of flying the flag at the State House grounds consider it an emblem of slavery that has become a rallying symbol for racism and xenophobia in the United States.
Supporters see it is a symbol of the South's history and culture, as well a memorial to the roughly 480,000 Confederate casualties during the 1861-65 Civil War. That figure includes the dead, wounded and prisoners.
Republican South Carolina Governor Nikki Haley said on Monday the time was right to take down the flag, which was put up at the State House a half century ago as resistance to federal efforts to end segregation in the South was at its peak.
Haley called on lawmakers, whose normal legislative year wraps up this week, to address the issue over the summer and said she would order a special session if they did not.
The legislature will consider the state budget in Tuesday's session but could also take up the flag issue.
Doug Brannon, a Republican House member, has said he plans to introduce the legislation this summer. It would take approval of a two-thirds majority vote by both chambers of the legislature to undo the state law that requires the flag at the capital.
That law was the result of a 2000 compromise that removed the flag from its earlier position atop the State House.
The flag issue was showing signs of spilling over into Mississippi, another of the seven former Confederate states. House Speaker Philip Gunn said on Twitter that the Confederate emblem in his state's flag had to go.
Virginia, which had also been part of the Confederacy, will no longer allow specialty license plates for the Sons of Confederate Veterans group that feature the flag, Governor Terry McAuliffe said on Tuesday.
Wal-Mart Stores Inc, the biggest U.S. retailer, said it is pulling all Confederate flag merchandise from its stores, and Sears Holding Corp said it would remove Confederate flags being sold by third parties on its website.
The shooting at Emanuel African Methodist Episcopal Church last week came in a year of intense debate over U.S. race relations, sparked by the killings of unarmed black men by police officers in Ferguson, Missouri, New York City and Baltimore. The outcry has spawned a reinvigorated civil rights movement under the "Black Lives Matter" banner.
Roof was arrested on Thursday and charged with nine counts of murder for the attack on "Mother Emanuel" church. He is the apparent author of an online racist manifesto.
President Barack Obama will attend Friday's funeral of Reverend Clementa Pinckney, a state senator and pastor of the historic church. He was one of the nine people killed on Wednesday.
(Additional reporting by Steve Holland in Washington and Nathan Layne in Chicago; Writing by Frank McGurty; Editing by James Dalgleish)