Most, if not all fresh beef,pork and chicken sold in the major UK supermarkets is 100% British.
That wonβt change.
The risk comes with future trade deals if we give in on farming standards with Australia.. For example the US will push likewise for such concessions and the standards drop again.
Iirc, the US food lobby were also talking about pushing for reduced labelling requirements so that knowing the origin of the meat by the packaging wouldn't be clear.