In exceptional circumstances, where the overall functioning of the area without internal border control is put at risk as a result of persistent serious deficiencies relating to external border control as referred to in Article 21 of this Regulation or as a result of the non-compliance of a Member State with a Council decision referred to in Article 19(1) of Regulation (EU) 2016/1624 of the European Parliament and of the Council, and insofar as those circumstances constitute a serious threat to public policy or internal security within the area without internal border control or within parts thereof, border control at internal borders may be reintroduced in accordance with paragraph 2 of this Article for a period of up to six months.
In imthosca eisceachtúla ina gcuirtear feidhmiú foriomlán an limistéir gan rialú ag teorainneacha inmheánacha i mbaol mar thoradh ar easnaimh thromchúiseacha leanúnacha a bhaineann le rialú teorann seachtraí dá dtagraítear in Airteagal 21 den Rialachán seo nó de thoradh Ballstát gan cinneadh ón gComhairle dá dtagraítear in Airteagal 19(1) de Rialachán (AE) 2016/1624 ó Pharlaimint na hEorpa agus ón gComhairle a chomhlíonadh, agus a mhéid is baol tromchúiseach na himthosca sin do bheartas poiblí nó do shlándáil inmheánach laistigh den limistéar gan rialú ag teorainneacha inmheánacha nó i gcodanna de, féadfar rialú teorann ag teorainneacha inmheánacha a athbhunú i gcomhréir le mír 2 den Airteagal seo ar feadh tréimhse sé mhí ar a mhéad.