ACPO lead on public order Chief Constable Ian Learmonth said:
"Mutual aid between police forces across the United Kingdom has always been an important part of keeping the community safe. While we serve our local communities with pride, the police service has a wider responsibility to ensure public safety and the rule of law across the country. When police colleagues from any part of the UK request assistance there is a legal and moral duty on us to consider that request and support it in the most appropriate way we can. Indeed, we were grateful for the prompt and unreserved support we received from colleagues in Scotland during the serious disorders experienced in parts of England in August only last year.
"Joint training has already taken place between mainland officers and the PSNI over recent years, and the tactics and equipment used in Northern Ireland is familiar to officers from several forces. No unit on mutual aid would be deployed without PSNI support or to an area where the threat and risk was so great as to be disproportionate to their safety. PSNI officers have also previously deployed to the mainland, and worked with colleagues here on public order events.
"It is important to remember that public order officers are volunteers. In a situation of mutual aid deployment to Northern Ireland, officers from England and Wales would be asked to volunteer for that duty.
"Within the demands of the service we will, of course, always seek to liaise closely with staff associations to ensure that deployments are properly mounted and appropriate."