IN A MESSAGE read by a tearful House clerk, Speaker Robert DeLeo announced he is resigning his position on Beacon Hill at 6 p.m. on Tuesday, setting the stage for the ascension of Majority Leader Ronald Mariano of Quincy to the top position in the chamber on Wednesday.

Shortly after the announcement just before 2 p.m., the speaker’s office said DeLeo would give a farewell address Tuesday afternoon and a caucus to elect a new speaker will be held on Wednesday.

Mariano is not expected to face any opposition for the speaker’s job, as Rep. Russell Holmes of Boston, who announced December 18 that he was running for speaker, said on Monday that he decided not to pursue his candidacy and informed Mariano of his decision last Wednesday.

DeLeo, in his statement, offered no insight on what job he might be taking at Northeastern University. DeLeo disclosed on December 18 he was talking to Northeastern about a position

“This House has consistently led the way and provided solutions to some of the most complex and challenging public policy problems of our time,” DeLeo said in his statement. “It is a comfort for me to know that, through our joint efforts, when I leave I do so with the knowledge that the House is well positioned for continued success.”

DeLeo and Mariano carefully orchestrated the speaker transition, with Mariano lining up votes over a period of years with DeLeo’s blessing. It was an arrangement that allowed DeLeo to leave whenever he wanted, which turned out to be after 12 years in the House’s most powerful position.

As the handoff from DeLeo to Mariano went public, a handful of progressive members raised objections and Holmes said he intended to launch a long-shot challenge to the majority leader. “Obviously this is going to be a very tough fight,” Holmes said on December 18. “I just plan on appealing to folks’ awareness that this building is operating in a way that is counterproductive to our constituents.”

Holmes described the House as a “poisoned tree,” and said “if you don’t yank this tree and uproot it, it will continue in the same way it has for 300 years, where people of color, women, and progressives are not part of the conversation.”

Holmes said on Monday that he changed his mind last week after talking to members about his candidacy for speaker and realizing that he had no chance of winning. He said he called Mariano on Wednesday and informed him he would not be running against him. Holmes said the two men had a very frank discussion about their differences and Holmes said he advocated for a more transparent, more open House.

Holmes said Mariano told him he had heard similar concerns from some other members in his discussions with them.

Holmes said Mariano did not offer him any assurances or any position. (DeLeo removed Holmes from leadership in 2017 after he suggested minority groups in the House should get involved in selecting the next speaker.) “No, he didn’t offer me anything. I didn’t ask for anything,” Holmes said.

DeLeo’s message was read into the House record by clerk Steve James, who struggled to finish it, tearing up with emotion. Members in the chamber applauded when James finished reading the letter DeLeo had written.

Gov. Charlie Baker issued a statement praising DeLeo’s work ethic and sense of  balance. “He put in the time, and on many issues – gun control, domestic violence, child welfare, wage parity, transportation, education, criminal justice and police reform – he worked hard to find common ground among competing voices.  That focus on deliberation and discussion made the end result better, and has created a positive, lasting legacy across state government.  Even though we had our fair share of disagreements, he always heard me out, and I will always be grateful for the courtesy he and his leadership team showed our cabinet secretaries and commissioners.”

Senate President Karen Spilka issued a statement offering congratulations “to my partner and friend, House Speaker Bob DeLeo, as he embarks on the next chapter of his long and accomplished career.”