President Obama to Announce Major Immigration Executive Action Thursday

— -- President Obama will announce a major executive action on immigration reform in prime time on Thursday, the White House said today.

"Our immigration system has been broken for decades -- and every minute we fail to act, millions of people who live in the shadows but want to play by the rules and pay taxes have no way to live right by the law and contribute to our country, White House Press Secretary Josh Earnest wrote on the White House website.

"So tomorrow night, President Obama will address the nation to lay out the executive actions he’s taking to fix our broken immigration system."

The president will then travel to Del Sol High School Las Vegas on Friday "to discuss why he is using his executive authority now, and why Republicans in Congress must act to pass a long-term solution to immigration reform," according to Earnest.

President Obama has invited senior lawmakers to the White House tonight for dinner to explain his immigration decision. Earnest confirmed Obama will dine tonight with a group of 18 top Democrats from the House and Senate.

The most controversial aspect of Obama’s planned action is likely to be an order to, on a temporary basis, exempt from deportation and grant work permits to as many as 5 million undocumented immigrants.

White House Chief of Staff Denis McDonough is being dispatched to Capitol Hill on Thursday for lunch with Senate Democrats, a move that presaged the announcement.

On Wednesday, Democrats took to the Senate floor to defend President Obama’s forthcoming executive action, saying the House could have avoided it by passing immigration reform themselves.

"I’m glad he’s going to in the next couple of days for sure to use his constitutionally established authority to fix our broken immigration system as much as possible,” Senate Majority Leader Harry Reid said.

Sen. Chuck Schumer, D-N.Y., added: "The dithering and dawdling on the House side is particularly perplexing because our bill would achieve so many goals that republicans claim are part of their agenda."

ABC's Devin Dwyer and Arlette Saenz contributed reporting.