While the new labor contract at UPS (UPS -1.16%) is expected to pass the vote on June 22, in the video below, Fool analyst Blake Bos tells investors that they will want to watch that vote very carefully. A strike back in 1997 cost UPS $650 million in lost business, and any such similar disruption now could be a catastrophe and a huge win for competitor FedEx (FDX 0.92%). Blake describes the relationship between management and workers at UPS, and tells investors some of the key labor challenges that the company will face going forward.