Two potential Boston mayoral candidates coming from the right – Councilors Ed Flynn and Erin Murphy – will have to duke it out to decide who takes the lead mantle to take on progressives in the next city election.

While Flynn and Murphy are now allies, they could be climbing over each other for the top position should newly-re-elected Mayor Michelle Wu leave or decide to run for higher office in the next few years.

But which is the true voice of the Wu resistance? Will they remain a team or will they branch off on their own? The mayoral race isn’t big enough for two moderates in left-leaning Boston.

Their own future mayoral ambitions may soon test their alliance and lead to clashes. They will have to decide which one is running and that day could come sooner than later if Wu – who has obvious national ambitions – leaves before her second term comes up.

Both Flynn and Murphy have built-in advantages – they were easily re-elected last November – but it’s unclear which will be the favorite of moderate to conservative voters in the future.

Flynn, son of former Boston Mayor Raymond Flynn, has the name recognition, energy and ambition to succeed, important elements in a citywide race.

But Flynn, from South Boston, is only a district councilor while Murphy is an at-large councilor, meaning she draws voters from all across the city every two years. Murphy finished third in the at-large race last year, drawing 46,360 votes.

By contrast, Flynn garnered only 8,600 votes to win his district race, getting 86% of the vote.

But Flynn’s father,  Raymond, served as mayor from 1983-1993 and his name is revered in many parts of the city. Ray Flynn stepped down from the mayor’s office in 1993 when he was named U.S. Ambassador to the Vatican by President Bill Clinton.

Murphy so far seems content to let Flynn be more out front on major issues, a role he embraces.

But it also means Flynn is the one taking the risk of being humiliated at the hands of Wu and her hardball politics. The far left mayor has largely tried to either ignore or marginalize him – the same strategy she uses against Murphy.

Wu and her allies like the Boston Globe barely mention either Flynn or Murphy and their initiatives. Flynn press releases go straight to the Globe garbage bin.

And unless WGBH decides to have an “Ask the Councilor” segment, they will be ignored by other liberal media as well.

Murphy has been trying to increase her profile over the last few months, putting out a glossy online newsletter on Monday honoring Martin Luther King, Jr.

“On Martin Luther King, Jr. day we honor a leader who reminded us that justice is not inevitable,” Murphy said. “For me, this day is a reminder that public service carries a responsibility to listen closely, to stand with communities who have too often been ignored, and to keep pushing for a city where opportunity is real and shared.”

That language seems more geared for progressives than moderates, indicating Murphy may be resisting a label as a conservative and wants to make inroads with more liberal voters.

Boston’s demographic is rapidly changing, and any future mayoral contender can no longer just appeal to just old time Boston – white and moderate to conservative Irish Americans.

That’s why Flynn – who represents parts of Chinatown – sometimes posts social media messages in Mandarin. He doesn’t want to be pigeonholed as just a conservative.

Councilor Erin Murphy (Staff Photo By Stuart Cahill/Boston Herald)