Vincent Orange thinks the council should have the ability to oust the city’s chief executive. (Nikki Kahn/The Washington Post)

City lawmakers would gain the power to expel the mayor under a proposed charter amendment set for a D.C. Council vote Tuesday.

Vincent B. Orange (D-At Large) has introduced emergency legislation that would permit the legislature, by a five-sixths vote, to boot the mayor or soon-to-be-elected attorney general from office following a “gross failure to meet the highest standards of personal and professional conduct.”

The measure, which would not go into effect until ratified by voters in a referendum, would reset the historic balance between the branches of District government that has persisted since the Home Rule Act was passed by Congress in 1973.

Orange, through his chief of staff, declined to comment on the measure Monday. But in a memorandum sent to colleagues Friday, Orange explained the measure mirrors provisions in the recently enacted ethics bill providing for the expulsion of council members. The mayor and AG, he wrote, “should be held to the same obligations to public office as every other public official.”

“Given that the next election cycle is currently underway, with several candidates already announcing runs for office, there exists an immediate need for this emergency to provide the Council with the appropriate means to ensure that all members of the government are operating ethically and to solidify the standards to which those considering running for Mayor or Attorney General will be held,” the memo continued.

Orange, together with colleague Jim Graham (D-Ward 1), introduced a permanent version of the bill earlier this year. But Chairman Phil Mendelson (D), who retained control over the bill, has not scheduled a hearing on the measure or otherwise moved it along.

The emergency, Orange wrote on Friday, is needed to give elections officials “appropriate notice to include this on the next ballot.”

Mendelson said Tuesday that he had “some concerns” about Orange’s bill — both on the substance of the bill and on his choice of emergency legislation to accomplish it. In any case, Mendelson said, a permanent bill would have to pass to properly authorize the needed voter referendum.

Rather than expulsion, Mendelson suggested it was “worth looking at” whether an impeachment procedure might be incorporated into the charter. “That is typically the way a legislature deals with an executive that is not fit for office,” he said.