A move to raise security guards' pay has stalled because many firms are worried that it may increase their costs.
This means that for the foreseeable future, a security guard's monthly basic salary of $800 will continue to be $200 less than what a cleaner gets.
The impasse could hobble the labour movement's progressive wage model, which was introduced in June last year to increase workers' salaries through better skills and higher productivity.
So far, the National Trades Union Congress (NTUC) has set minimum pay benchmarks in sectors such as cleaning, transport and hotel.
It began talks with security associations here last month to set the basic pay at $1,000, on a par with what was set for cleaners last year.
But Mr T. Mogan, president of the Security Association of Singapore which represents about 130 firms, believes that higher basic pay will increase overheads. This is because most of a guard's salary comes from overtime - calculated at 1.5 times the regular pay.
"We are not like landscaping or cleaning, which are based on a straightforward eight hours of work per day without overtime," he said.
He also argued that companies already have their own salary structures, and they need the flexibility to reward and promote staff without having to adhere to external rules. "It is for them to support our idea, not for us to agree to their way of doing things," said Mr Mogan of NTUC's new plan.
Mr Robert Wiener, president of the Association of Certified Security Agencies which represents more than 110 firms, is not against the $1,000 basic salary. But he wants any pay hike to be part of a more comprehensive solution to solve the sector's manpower crunch.