Cameras on Border would 'be legitimate targets and endanger peace process'
Cameras and other infrastructure erected along the Border after Brexit would be deemed a "legitimate target" and so risk undoing the peace process, the UK's Chancellor Philip Hammond has warned MPs.
He said any physical aspects put in place to control the crossing would be seen as an affront to "those who do not recognise" the Border on this island.
There are concerns that even using number-plate recognition technology would breach the aim of avoiding a hard Border.
Mr Hammond reiterated to the UK Parliament's Treasury Committee his Government's intention to avoid any infrastructure and to maintain the Border "broadly as it is now".
He warned: "Number-plate recognition requires cameras; not necessarily at the Border, but it will certainly require cameras to be installed.
"The challenge in Ireland is that those who don't recognise the Border will see any physical manifestation of a border as a legitimate target and that infrastructure will need protection.
"What we don't want to do is go back to the days when we had a hard protected infrastructure on the Border because that would undo much of the progress that has been made since the Good Friday Agreement."
He said Ireland had a "great deal of interest" in the outcome of the Brexit process, not only because of the Border issue, but also because of east-west trade.
Mr Hammond said that depending on the outcome of the future-relationship phase of the Brexit talks, the Border issue would become more or less difficult to resolve.
He rejected the notion that any checks would be needed at the Border and pointed out that Northern Ireland and the Republic already operated two regimes on excise for cigarettes and alcohol without any physical infrastructure.
He explained: "That hasn't happened by coincidence. It has happened because a huge amount of work and a huge amount of commitment have gone in on both sides of the Border to allowing us to have that separate policy, without the need for a hard infrastructure.
"And it works pretty well."
Conservative MP Alister Jack said Ireland was the "Achilles heel" to the idea of the UK leaving the EU without a deal and moving forward on World Trade Organisation terms.
Meanwhile, in the Northern Ireland Affairs Committee, MPs were told that a hard Border could be created around Northern Ireland after Brexit, even if the UK initially agreed a soft Border with the European Union.
Economist Paul Mac Flynn raised concerns about proposals that only large businesses could be required to register their imports and exports.
He told MPs: "I think the danger is that we could start out with a soft Border and end up with a hard Border, like the exemption for small and medium-sized enterprises.
"If you're somebody who is going to want to get around a tariff border, all that says to you is. 'Right, don't use trucks, use vans.' Then we start checking vans. Before you know it, we're checking everyone."