UK bans Hamas in its entirety
London said last week it was no longer possible to make a distinction, assessing that Hamas "commits, participates in, prepares for and promotes and encourages terrorism".
"The Islamist terrorist group Hamas has today become a proscribed terrorist organisation in the UK in its entirety following parliament's approval," the Home Office said.
"This means that members of Hamas or those who invite support for the group could be jailed for up to 14 years."
Israel has welcomed the move, which follows similar action by the United States and the European Union.
But Hamas itself has called the UK move "a crime against our Palestinian people and all their history of struggle".