Two weeks out from the Democratic primary, mayoral hopeful and Connecticut State Sen. Toni Harp ARC ’78 pocketed another major endorsement Tuesday, winning the support of Connecticut Sen. Chris Murphy in her quest for New Haven’s top seat.

After a string of summer endorsements from all corners of the city’s Democratic establishment, Murphy’s was the second vote of confidence this month to broaden that backing beyond New Haven and the first to come from a figure on the national stage. Addressing a crowd of supporters at the Farnam Neighborhood House, a youth center in Fair Haven, Murphy praised Harp as a visionary with the courage and experience to lead the city on day one of her tenure.

“I am so proud to be here today to offer my full, unconditional, enthusiastic endorsement to Toni Harp to be the next mayor of the city of New Haven,” Murphy said. “No one else can deliver that kind of package of vision, of courage and of experience as the next mayor of this city.”

As a former colleague of Harp’s in the state senate, Murphy detailed her legislative accomplishments — including funding stem cell research and setting up the state’s Office of Child Protection — and described her effectiveness in co-chairing the body’s appropriations committee.

Murphy’s vote of confidence came two weeks after Connecticut Gov. Dannel Malloy threw his weight behind Harp, which followed endorsements from the Democratic Town Committee, Yale’s Unite Here Locals 34 and 35 unions and a majority of city lawmakers on the New Haven Board of Aldermen.

Those endorsements have positioned Harp as the perceived frontrunner in the race to replace retiring New Haven Mayor John DeStefano Jr.

In the most competitive race in decades, Harp will square off against three opponents in a Sept. 10 Democratic primary: Hillhouse High School Principal Kermit Carolina, Ward 10 Alderman Justin Elicker FES ’10 SOM ’10 and Henry Fernandez LAW ’94, a political consultant and former New Haven economic development administrator.

As a 21-year incumbent state senator, Murphy said, Harp alone is positioned to “make sure New Haven gets what it needs from the state legislature” and to “build consensus in a “perilous time for cities across Connecticut.”

Introducing Murphy, Harp said she and her former colleague are “on the same page about this campaign’s priorities.” She called Murphy a “leading voice” in the U.S. Senate on many of the same issues she is targeting on the local level: public safety, jobs and education.

“We have been in the trenches together,” Harp said.

Prior to winning election to the U.S. Senate in 2012, Murphy represented Connecticut’s fifth district in the U.S. House of Representatives. Before that, he served in both houses of the state legislature, representing districts that do not comprise New Haven.

Saying his support would mean more than “just a paper endorsement,” Murphy pledged to “do whatever … however” to elect Harp.

“I’m ready to sign team Murphy up with team Harp to knock on doors over the next two weeks,” he said, promising to mobilize his email list of “over 100,000 people” to drum up volunteers.

Harp’s opponents fired back Tuesday afternoon at the Harp campaign for touting Murphy’s support, saying the endorsements of politicians and organized labor are a warped measure of the support of rank-and-file New Haven residents.

Fernandez called Murphy’s endorsement “literally irrelevant” and said the support of a national politician “won’t influence a single voter in the city of New Haven.”

He added that the public show of support in a Democratic primary is “quite embarrassing” for Murphy, saying he has never before seen a sitting U.S. senator make an endorsement in a contested mayoral primary election.

Both Fernandez and Elicker attributed Murphy’s endorsement to pressure from Locals 34 and 35, labor unions to which Elicker said Murphy “owes a lot of his success in the 2012 election.”

Carolina called the endorsement “disappointing,” citing controversy surrounding claims of tax delinquency leveled against Harp’s late husband as evidence that his opponent “can’t hold those around her accountable.”

Fernandez and Elicker challenged Murphy’s assertion that Harp’s time in Hartford readied her to lead New Haven out of its dire fiscal straits. Both alleged that Harp herself has admitted to being uninformed about the city budget.

“She isn’t prepared on day one to address the city’s fiscal problems,” Elicker said. “She needs to learn about them first. I understand the operational details of how the city runs and the budget problems we face.”

Murphy did not share that sentiment. He said Harp “knows how to get things done.”

“She’s got the relationships that will make it happen,” he said. “She will show up with the ability to pass a budget.”

Harp has represented New Haven in the state senate since 1993.