belfast harbour. where many of the products used by households and businesses enter northern ireland. last year the equivalent of more than half a million freight vehicles used the harbour to bring goods back and forward across the irish sea. at the minute, this system runs smoothly and with minimal paperwork. but that could all be about to change. on the ist of january, when those vehicles leave great britain and come to northern ireland, it'll be as if they are entering the eu. and the eu will need to verify that everything inside those containers is ok to enter the single market. that means new checks and extra documentation — asjess sergeant from the institute for government think tank explains. the ni protocol requires eu law to be applied in northern ireland in certain areas such as customs, agriculture regulation and product standards. so what that means is that anything entering ni, needs to prove that it complies with those eu laws. and that'll mean there will need to be new paperwork, new ch