Five years ago the Daily Express was busy campaigning about how leaving the European Union would result in lower food prices, any talk that it would increase food prices due to additional trade-related paperwork was labelled "project fear".
Earlier this month:
Supermarket bills set to sour due to EU red tape. Ahhh yes the "new" EU red-tape we avoided by being members. Of course they use the language "new" to imply these are recent changes the EU have made, and as such trying to imply its the EU's fault. They're not, its the same import and export related paperwork and all the rest that all other countries around the world need to do in order to trade.
Obviously if you put up trade barriers - even if its tariff-free, there's still additional paperwork and delays and hence such additional costs, that's why we had a good deal as members because we were part of a trade block of 27 other countries, whereby all agreeing a common set of standards, we could avoid all the usual checks most other countries around the world need to do when trading.
You wanted a border between us, you've got one. Now deal with the consequences and take responsibility for your decision.