I mean, it's not just ham sandwiches. The repeated referral to a single item of food indicates you're trying to make this sound more ridiculous than it actually is. Invoking Covid is whataboutism anyhow. Covid already exists in the UK. It already exists in mainland Europe. It cannot be prevented anymore than establishing social distancing, wearing masks, and now rolling out the vaccine can prevent it. To use it as a comparison to a border control issue the UK has had plenty of time to prepare its workers for is the real excuse.