High Court rules on dual citizenship

WHY HAS LABOR SENATOR KATY GALLAGHER BEEN BOOTED FROM PARLIAMENT?

* The full bench of the High Court unanimously agreed that Katy Gallagher was a citizen of a foreign power when she nominated for election to parliament in May 2016, and therefore incapable of being chosen.

* British law did not impose an "irremediable impediment" to Gallagher renouncing her foreign ties before nominating.

* The procedure to renounce British citizenship was simple and the requirements not onerous.

* The issue for Gallagher was only ever to be the timing of her registration to sever her British links.

* Gallagher began her renunciation process a month before nominating to run for the Senate, but the registration was not complete until two weeks after she was elected.

* It was not enough for Gallagher to merely have taken steps to renounce her foreign citizenship, or foreign laws simply posing an obstacle.

* Gallagher needed to have actually divested herself of her British links before being chosen for parliament.