In 2013, the European Union placed the military wing of Lebanese party Hezbollah on its terror list, and London had proscribed the group's external security unit and its military wing in 2001 and 2008 respectively. Now, the UK plans to outlaw its political arm too.
"Hezbollah is continuing in its attempts to destabilize the fragile situation in the Middle East, and we are no longer able to distinguish
"Because of this, I have taken the decision to proscribe the group in its entirety."
The ban is a response to an Israeli bid to the members of the United Nations Security Council, filed earlier this month. Israeli representatives voiced their concerns over Hezbollah's further strengthening in the Lebanon and the establishment of extensive terror infrastructures, and also raised the need to prevent further Iranian entrenchment in Syria.
The British ban, which will come into force on Friday subject to parliament's approval, means anyone who is a member of Hezbollah or invites support will be committing a criminal offence with a potential sentence of up to 10 years in jail.
Explaining its decision, the British government said the organization continued to amass weapons in contravention of UN Security Council resolutions, while its support for Syrian President Bashar al-Assad had prolonged "the conflict and the regime's brutal and violent repression of the Syrian people".
There was no immediate reaction from Hezbollah to the British move.
The group controls three of 30 ministries in Lebanon's government, the largest number it has ever held, and has seen its regional clout expand too with fighters in various Middle East conflicts including neighboring Syria.
It does not acknowledge the existence of separate wings.
Jeremy Corbyn, leader of Britain's opposition Labour Party, once described Hezbollah as friends, a remark regularly seized upon by opponents for criticism.
"What do we see from his Labour Party? Hamas and Hezbollah friends, Israel and the United States enemies," Prime Minister Theresa May said last week.
Hezbollah was already considered a terrorist organization by multiple countries, including Israel, the US and members of the Arab League.