The expected announcement is the latest in a year-long string of efforts by government officials to putstrings on executive pay by companies that have received bailout cash.
While the community - which observes a strict rule of silence for 12 hours every night - does not need huge profit, extensive repairs to the monastery has recently put additional strain on the purse strings.
The union said Swissport had not met the claim for Sunday premiums and the pay offer they had put on the table included "unacceptable" strings attached.