In June 2016, McAleese urged the British to vote to remain in the EU. McAleese warned that Britain's departure could result in the return of border controls on the island of Ireland and a cause a "potential drift" in the peace process. McAleese said the "chances of customs controls being reconstituted are probably greater as they had been eliminated by EU laws, not Anglo-Irish efforts". McAleese challenged claims by Boris Johnson and Michael Gove who frequently repeated claims that the position on the island of Ireland would not change. McAleese said, "I don't know that to be (true) and they do not know that".