Obama to address Labor Day breakfast

President Obama will address a union-hosted Labor Day breakfast in Boston, White House officials confirmed Tuesday.

Several senior Democrats told the Globe Monday that Obama was planning to attend the annual Park Plaza event, sponsored by the Greater Boston Labor Council. The White House said it would be announcing additional details of Obama's trip "in the coming days."

The breakfast traditionally provides a venue for Democrats to dish red-meat rhetoric to a constituency historically allied with the party.

"I know the labor movement will be excited in Boston," Mayor Martin J. Walsh said Monday.

But the visit comes during a complicated stretch in Obama's relationship with organized labor. Unions have bucked the Democratic president this year over his trade and regulatory policies, which they call destructive to American jobs.

In June, Richard Trumka, the AFL-CIO's president, reportedly wrote to Obama, alleging he had "repeatedly isolated and marginalized labor and unions" during the debate over the Trans-Pacific Partnership.

One top Democrat who has joined with labor in criticizing Obama over the trade deal is expected to share the podium with Obama on Monday. US Senator Elizabeth Warren of Massachusetts used the Labor Day breakfast as something of a coming-out party in 2011, days before announcing her candidacy.

Things are rocky, too, between labor and Democrats on the state level, after the heavily Democratic Legislature sided with Governor Charlie Baker, a Republican, in a budget fight earlier this year. Party leaders ratified a major setback for public-sector unions, easing wider privatization at the MBTA. Union leaders argue the measure will mean more government work being performed by private contractors who will charge more but pay employees less.

That maneuver, which many in organized labor called a betrayal, prompted about 45 top labor officials and activists to huddle in June, where some strongly advocated finding primary challengers to Democratic lawmakers — an unusual demonstration of raw anger among traditional allies.

Nonetheless, a labor audience in a reliably blue state will put Obama in front of a friendly crowd. Both of the state's US senators have announced support for the Iran nuclear deal, negotiated by Secretary of State John F. Kerry, that Obama has placed atop his agenda.

"We're always the reliable welcome wagon for a Democratic president," one Democrat said.

The breakfast occupies something of a unique, if obscure, niche in Obama's own political record. In 2009, days after the death of US Senator Edward M. Kennedy, and with the field to succeed him still taking shape, a show of force at the event by then-attorney general Martha Coakley helped cement her momentum on the way to becoming the Democratic nominee. At the same time, the chilly reception given to US Representative Stephen F. Lynch, a former labor leader, because he had been noncommittal to Obama's health care bill, helped sap enthusiasm for his candidacy.

Coakley embraced the health care measure, but later lost to the Republican nominee, Scott Brown, a vocal opponent of the bill.

Brown's victory complicated passage of the bill, which ultimately became law several weeks after Brown took office.