The senior officials said Obama’s action planned for Monday at the White House would amend two executive orders. The first, signed by President Lyndon Johnson in 1965, prohibits federal contractors from discriminating based on race, religion, gender or nationality in hiring. Obama plans to add sexual orientation and gender identity to the list of protections, and order the Labor Department to carry out the order. The officials said that means the change will probably take effect by early next year.

President George W. Bush had amended Johnson’s order in 2002 to allow religious groups to hire and fire based upon religious identity. Churches also are able to hire ministers as they see fit. The senior administration officials said Obama will not change those exemptions.

The second order Obama will amend was signed by President Richard Nixon in 1969 to prevent discrimination against federal workers based on race, religion, gender, nationality, age or disability. President Bill Clinton added sexual orientation, and Obama will include gender identity in a change to immediately take effect.

Human Rights Campaign President Chad Griffin said: “With two strokes of a pen, the President will have a very real and immediate impact on the lives of millions of LGBT people across the country.”

The administration officials said the change for federal contracting will impact some 24,000 companies with 28 million workers, or one-fifth of the U.S. workforce. Many large federal contractors already have employment policies barring anti-gay workplace discrimination, as do 21 states. However, the Williams Institute at UCLA Law School estimates that the executive order would extend protections to about 14 million workers whose employers or states currently do not have such nondiscrimination policies.