UPS and the Teamsters union, which represents 260,000 of the delivery service's workers, are deadlocked on collective bargaining negotiations — as the company aims to offer delivery services seven days a week — and they don't seem to be close to an agreement as the union has already voted in favor of a strike, reports CNN.

Why it matters: The deadline for the two sides to come up with a new arrangement is August 1, and if they fail to do so it could lead to a devastating strike that may disrupt the nation's economy.

Between the lines: More than 90% of UPS' freight employees agreed to authorize a strike, and 93% of the union members who voted agreed on the measure as well, reports Fortune. The labor strike would be one of the largest in decades.

• Although it's been authorized, workers can't strike until after July 31 when the deal ends.
• UPS began offering Saturday delivery service last year and have proposed plans to expand to Sunday.
• The two sides are also discussing a two-tier wage system converting part-time workers earning $15 per hour into full-time workers earning the same amount. However, current full-time drivers earn an average of $36 per hour.
• Workers within the union are torn on this potential policy, which makes it more difficult to strike.

Threat level: UPS ships an equivalent of about 6% of the U.S.' gross domestic product around the country. A strike of this magnitude could stop those shipments and have a significant blow on the economy, per CNN.

Backdrop: The last time UPS had a strike was 1997, per Fortune. The company was concerned it could lose "hundreds of millions" of dollars, per the New York Times.

The bottom line: Though the pressure is mounting on both sides to close on a deal, there is still time between now and when the deal expires to finalize it.