WITH just three weeks to go until the UK votes on staying or leaving the European Union, Theresa Villiers has failed to produce a convincing case that border controls would not appear on this island in the event of a Brexit.
Immigration has been one of the fundamental issues of this campaign, put into sharp focus by the attempt by a number of Albanian refugees to land on the Kent coast at the weekend.
The group was rescued from the English Channel after their inflatable boat began to sink with the incident leading to calls by Ukip for increased coastal patrols and tighter border controls.
Given this sort of attitude, it makes little sense for the Leave camp to be completely relaxed about the only land border which would exist between an EU country and the UK following a vote in favour of Brexit.
However, this is the position that has been firmly maintained by the secretary of state during the course of the referendum campaign, despite a range of high level voices pointing to the inconsistencies in her argument.
The latest senior figure to weigh into the debate is Sir Hugh Orde. As a former PSNI chief constable and former head of the Association of Chief Police Officers, he speaks with considerable authority on the security implications for Northern Ireland following a leave vote.
In an article in The Irish Times, Sir Hugh said: ``It is inevitable that border controls would have to return - the whole Brexit argument is around this very point.''
Putting his case in a nutshell he added: ``If you shut the front door, leaving the back door open would be stupid.''
There is no doubt that such trenchant criticism by the well-regarded former chief constable is damaging to Ms Villiers and the Leave campaign.
The secretary of state has responded by maintaining there has been a common travel area with the Republic for nearly 100 years and that would continue if there is a vote to leave.
Her assertion that there were no border checks before the UK joined the EU will bemuse older readers who will recall queues at customs posts at Killeen and elsewhere.
The secretary of state insists the risks around retaining an open border `can and will be effectively managed.'
But it is not clear how that will happen or what the implications will be for those who live in border areas and travel between north and south on a regular basis.
An argument that seems to be based on `trust me, it will all be fine' is not likely to persuade people in Northern Ireland with genuine concerns about the reinstatement of any measures that would impact on the free movement of goods and people across the border.
Theresa Villiers is looking increasingly isolated as she clings to a position that bears little relation to reality.
