Hamas’ military wing has been proscribed in the UK since 2001, but in an announcement on Friday the home secretary will say the entirety of the Palestinian group should now be banned.
It means supporters of the group will face up to 10 years in prison under the Terrorism Act.
Setting out details in a speech on security at the Heritage Foundation in Washington, a conservative think tank which was previously aligned with Donald Trump on a number of his presidential policies, Ms Patel will say the current listing of Hamas as distinct political and militant wings “creates an artificial distinction between various parts of the organisation”.
She will say: “Hamas has significant terrorist capability, including access to extensive and sophisticated weaponry, as well as terrorist training facilities, and it has long been involved in significant terrorist violence. But the current listing of Hamas creates an artificial distinction between various parts of the organisation – it is right that the listing is updated to reflect this.
“This is an important step, especially for the Jewish community. Hamas is fundamentally and rabidly antisemitic.
“Antisemitism is an enduring evil which I will never tolerate. Jewish people routinely feel unsafe – at school, in the streets, when they worship, in their homes, and online.
“This step will strengthen the case against anyone who waves a Hamas flag in the United Kingdom, an act that is bound to make Jewish people feel unsafe.
“Anyone who supports or invites support for a proscribed organisation is breaking the law. That now includes Hamas in whatever form it takes.”
However the move will put further strain on efforts to build the conditions for a permanent agreement between the Israeli government and the Hamas-run government in Gaza towards a two-state solution, which the British government has said it is committed to.
Israeli-Palestinian peace talks, which were opposed by Hamas, broke down in 2014. Hamas does not recognise Israel's right to exist and has fought three wars with it since taking control of Gaza.
Rare Palestinian parliamentary elections scheduled for May 2021 were postponed and the last poll, held in 2006, saw Hamas win a landslide victory.
Proscription makes it a criminal offence to belong to an organisation in the UK or overseas, or even to express an opinion or belief that is supportive of a such a group.
Wearing clothing that suggests an individual is a member or supporter of a proscribed organisation, or publishing an image of an item of clothing, flag or logo that would lead to the same conclusion, is also a criminal offence under the Terrorism Act 2000.
Ms Patel will also use her speech to warn about the “overt and covert action that undermines the United Kingdom’s national security” from countries including China, Russia and Iran.
“We respect the people of every country,” the home secretary will say. “But we will condemn all state actors who do wrong by us or our allies, and we will do whatever it takes to keep our country safe.
“If we want a future in which we are prosperous, happy, and free, we will have to continue to work for it – extremely hard. And that means cooperation among allies and a shared understanding that if we don’t have security, we will have none of the things we want – and all the things we don’t want.”
In 2017, Ms Patel was forced to resign from Theresa May’s government after it emerged she had conducted secret meetings with the Israeli government and discussed giving British foreign aid money to the country’s military.