"We will not impose import duties on EU food."

Suppose they do decide to let food from the EU in without import duties. Won't there be a need for paperwork to prove a) those imports come from the EU and b)that they are foods? And won't this lead to delays and added costs?

But we will also lose EU negotiated trade relationships with some countries we get food from, having to wait until WTO is negotiated or other deals are struck.