A service station business is investigating complaints that staff are potentially having to cover costs from their own wages when customers drive off without paying for fuel.
Kenny's Convenience Stores, which has six outlets across Northern Ireland, said it has "robust employment practices" and takes any complaint "very seriously".
SDLP councillor Ryan Wilson, the party's workers' rights spokesperson, said he became aware the concerns on social media and received images of what is described as a staff "training document".
The paper, which includes Kenny's branding, lists procedures for so-called drive-offs - when petrol station forecourt customers fail to pay for their fuel.
It says that when a customer enters the store, the fuel sale becomes the responsibility of cashier who serves them, adding: "CCTV will clarify this, you will then have to pay for it yourself."
It adds: "Can we really expect our employer to pay for our silly mistakes?"
The document includes a section to sign, and says failure to comply with the policy could result in "disciplinary action or dismissal".
Mr Wilson, a trade union worker, said he has written to Kenny's and has been "inundated with messages from current and former staff" after sharing his correspondence on Facebook.
"Numerous staff have reported to me that they have had to hand over cash payments if a customer failed to pay for their petrol, some also reported that any till shortages also had to be paid back," he added.
The Antrim and Newtownabbey councillor said he was "horrified" at the idea of "low-paid staff, many of whom are only young people in their first job" being impacted and called for any payments to be refunded.
In a statement a spokeswoman for Kenny's said: "As a company that employs over 130 people in six stores throughout Northern Ireland, we have robust employment practices in place to support and protect all our staff and we take any complaint very seriously.
"Once we became aware of this issue, we commenced an internal investigation and are progressing this as a matter of urgency."
