Northern Ireland effectively remained in the EU’s single market for goods after Brexit.

The means the EU’s new General Product Safety Regulation (GPSR) will apply in Northern Ireland from 13 December.

A spokesperson for eBay said: “We are supporting sellers as much as we can to understand and comply with this complex regulation.

“For several months we have had GPSR fields and functionalities live to allow sellers to add required information to their listings, we have been communicating with them since June, engaged with them through forums such as eBay Open and our seller council, and are providing sellers with partners to help them get compliant.”

An Amazon spokesperson said: “We have made sellers aware of the EU GPSR and the relevant requirements ahead of it being introduced.

“Sellers are required to submit the required information for listing on our EU-based stores and we will continue to provide updates to sellers with listings on our UK store.”

Among the requirements of GPSR is the need for a “responsible person”, which is effectively a compliance officer or agent.

For goods which are manufactured outside the EU or Northern Ireland the responsible person must be based in the EU or Northern Ireland.

That is a particular difficulty for businesses in Great Britain which are selling direct to consumers via an online platform and do not have a NI-based distributor or wholesaler.