Officials in Lac-Mégantic, Que. have set a deadline for the US-based railway at the centre of the derailment that set off explosions and killed up to 47 people.
The town says Montreal, Maine & Atlantic (MMA) has not paid workers who are cleaning up millions of litres crude oil that spilled in the disaster almost three weeks ago.
When some of the workers threatened to walk out, the town paid them a total of four-million dollars.
The town has sent a letter to MMA demanding to be reimbursed, and the letter calls on the railway to reply by 12 p.m. ET today.
Meanwhile, preparations continue for Saturday's memorial service for the victims.
Maine Governor Paul LePage will be among those at the service in Lac-Mégantic.