LONDON (AP) — A parliamentary committee is warning of catastrophic consequences if Britain fails to put a new customs system in place before the U.K. leaves the European Union in 2019.

The Public Accounts Committee released a report Tuesday outlining the risk of "huge disruption" for business, with border delays causing "massive backups" at the port of Dover and food rotting in trucks if the system doesn't work properly.

The Revenue and Customs Service began developing the new system before last year's vote to leave the EU, and it is scheduled to be operational by January 2019. The committee says meeting this deadline is crucial because Brexit may lead to a fivefold increase in customs declarations.

The dire warning comes as legislation on Britain's withdrawal from the EU returns to Parliament on Tuesday.