We are required to allow free passage of EU members across our borders.

Seeing as you obviously missed it in the link I posted, here are the relevant facts.

These rights do not undermine the UK’s ability to control its borders, for three principal reasons.
First, the largest category of migrants to the UK come from outside the EU, and are not entitled to rely on EU laws on freedom of movement.[3] The UK’s ability to restrict entry to this group is unaffected by its membership of the EU.
Secondly, whereas many Member States have replaced individual controls with a common policy at their common frontier (known as the Schengen Area),[4] the UK chose to retain its right to independent border control and is entitled to check the identity of every individual entering the country.[5]
Thirdly, EU law does not provide nationals from other EU Member States with an unlimited right to enter or remain in the UK. Most importantly, the right to live in the UK without any conditions or formalities only lasts for three months.[6] In addition, the right is subject to limitations “on grounds of public policy, public security or public health”.[7] Specifically, the UK retains the right to restrict the freedom of movement and residence of EU citizens and their family members, where their personal conduct represents “a genuine, present and sufficiently serious threat affecting one of the fundamental interests of society”[8] and the home Member State of any expelled EU nationals must allow those nationals to re-enter their territory.[9]

Got it? It really is simple. We control our own borders already.