Mayor Bloomberg yesterday called upon President Obama to “lead the charge” for bolstering the nation’s ineffective gun laws, starting with his State of the Union speech tonight.

“What we need is the courage for somebody to stand up and do something instead of just talk about it,” the mayor declared at a City Hall press conference.

“With our country still mourning the victims of Tucson,” the mayor urged the president to “lead that charge the way President [Lyndon] Johnson did” in 1968 after the assassination of the Rev. Dr. Martin Luther King Jr.

Bloomberg made his pitch at a City Hall press conference while standing with Martin Luther King III and other relatives and friends of victims of gun violence, including the school rampages at Columbine and Virginia Tech.

Several made brief poignant statements before the mayor spoke, including Christina Vaccarino, whose son died trying to stop a holdup in Queens in 1994.

“My son Glenn was killed buying bagels and coffee,” Vaccarino said.

White House spokesman Robert Gibbs was noncommittal on the president’s speech. But he said he wouldn’t “doubt” the Tucson tragedy and gun issues would be mentioned.