Any infrastructure on the border will give violent dissident republicans an opportunity to rally, boost recruitment and attack, top PSNI officers have warned MPs.

Drew Harris, the Deputy Chief Constable of the Police Service of Northern Ireland, said there remains a severe terrorist threat in the North. This year there has been four attempts to kill police officers, as well as 58 shooting incidents and 33 bombing incidents, he said. 

Mr Harris told the House of Commons Brexit Committee during a hearing in Armagh that dissident terrorists are focused on the border issue in the context of Brexit.

“Obviously violent dissident republican groups see this as an area that is contentious, which will give them in effect a further rallying call to try and engender support and try and drive their recruitment,” Mr Harris said.

“It is of concern. We know from information that we have that they have a focus on this, that they see it as an opportunity.

“The UK have said that there will be no infrastructure on the border because that will be an obvious point for dissident groups to rally around and attack, but also try to engender support and sympathy in local communities and further afield.”

Assistant chief constable Stephen Martin told the committee that an attack in Northern Ireland from dissidents remains highly likely.

He said that while the dissidents do not have the capability and capacity that the IRA had during the Troubles, they have demonstrated an ability to kill.

“If there was infrastructure such as you describe, whether it be buildings or people that reemphasised the border in the physical, tangible, visible, way, I think it is highly foreseeable that dissident republicans would seek to take action against that, and that could include attacking the buildings and the people,” he said.

Asked if he believed that threat would exist even for cameras, Mr Harris said there already exists an extensive number plate recognition system in Northern Ireland, and it does get regular criminal damage.

The Committee was also hearing evidence from HMRC, the UK’s equivalent of the Revenue Commissioners. Evidence in private was heard from a number of trade bodies as well as drinks giant Diageo. Members also visited the border between Co Armagh and Co Monaghan at the village of Middleton.

The senior PSNI officers also told the committee that a joint report between the Gardai and the PSNI on the implications of the UK’s EU withdrawal has been commissioned. A first draft has been completed. The two officers will travel to Dublin next week to meet senior garda offciers, including the acting Garda Commissioner.

Mr Harris said that during the 1980s there was a major problem with cross-border burglaries of older people in their homes.

He said many of the culprits escaped justice by heading over the border.

The Deputy Chief Constable outlined a number of shared European initiatives, such as the European Arrest Warrant, shared information systems and joint investigation teams, which have helped in the fight against crimes including human trafficking and drug smuggling.

He said many of the culprits escaped justice by heading over the border. He said there focus was in ensuring that people in border communities continue to feel they are safe.

Mr Martin added: “What happens as a consequence of Brexit, that sense of knowing that you will be brought to justice, and that the Republic of Ireland administration and ourselves can come after you, bring you to book, bring you to justice, must be retained.”

Simon York, Director of HMRC's Fraud Investigation Service, told the committee that he did not believe there was a requirement for any infrastructure on the border post Brexit to deal with smuggling.