A massive Teamsters labor contract deal for more than 200,000 UPS workers failed to get a majority vote in favor -- but the union said the deal has still been ratified because of a provision in its governing principles.

The unusual outcome for the largest collective bargaining agreement in North America presents a predicament for the International Brotherhood of Teamsters and its members at UPS. The company and its shareholders have been hoping approval of the deal -- covering UPS drivers, package sorters and loaders, operations and dock workers -- would reduce the risk of labor turmoil before the busy holiday shipping season.

The union sent a message to its members reminding them that a “no strike/no lockout clause” remains in effect.

Teamsters leadership has come under pressure from dissident groups of members challenging deals reached by the union.

The Teamsters said out of 209,043 members eligible to vote, only 92,604, or 44.3 percent, cast ballots.

Of those that cast ballots, 54.2 percent voted against the deal.

In a message to members after the ballots were counted, the Teamsters said: “In such circumstances where less than 50 percent of the membership votes on a final contract offer, the International Constitution provides that ‘a two-thirds (2/3) vote of those voting shall be required to reject such final offer…’ Failure to reject the offer by at least two-thirds vote of those voting “shall require the negotiating committee to accept such final offer or such additional provisions as can be negotiated by it.”

“The International Constitution does not give the [negotiating committee] an option in these circumstances...” the Teamsters said. “Thus, the National Master UPS Agreement has been ratified.”

Still, the union said it “fully intends to demand that UPS return to the bargaining table to address a number of member concerns” with the labor contract. And the full agreement is not final until negotiators hammer out supplemental agreements.

UPS said it will “meet with the Teamsters leadership in the near future to discuss next steps,” and added that “Business continues as usual at UPS.”

Sean O’Brien, president of Teamsters Local 25 in Boston, called the union leadership’s statement “outrageous.”

“It’s clear that the members voted to reject the contract,”  O’Brien said. He said Teamsters leaders Jim Hoffa and Denis Taylor “are using a loophole in the constitution.... This is going to set back not only the Teamsters but the labor movement, back 40 years.”

O’Brien said he thinks the union’s executive board should discuss the matter and decide whether to implement the contract.

The union had said the new labor contract would increase pay, allow more full-time opportunities for part-time workers and provide for some increases in the company's contributions to benefit funds including pensions. It would also create a new classification of drivers for workers handling weekend shifts, as online shopping continues to surge and increase demand for deliveries on the weekends.

O’Brien criticized the contract for allowing a two-tier wage system and not meeting a $15 an hour starting rate that other companies have announced, including Amazon.

It's not the only Teamsters contract deal that failed to get a majority vote. Also Friday, a UPS Freight agreement to cover about 11,000 Teamsters was voted down with 66.2 percent of eligible members voting.

And earlier this week, UPS said it was "disappointed by the vote result" for a Teamsters deal covering UPS aircraft mechanics, and planned to meet with Teamsters leaders and the National Mediation Board controlling the contract negotiations to discuss next steps.