Britain on Monday declared global Islamist group Hizb ut-Tahrir as a proscribed terrorist group, making it a criminal offence to belong to what it described as an antisemitic organisation.

Britain's proscription of the Sunni Islamist political group - which puts it on par with al-Qaeda or ISIS - will come into force from Jan. 19 if agreed by parliament, the Home Office said.

"Hizb ut-Tahrir is an antisemitic organisation that actively promotes and encourages terrorism, including praising and celebrating the appalling 7 October attacks," Home Secretary James Cleverly said, referring to the rampage by Palestinian militant group Hamas through southern Israel that killed 1,200 people.

Hizb ut-Tahrir's praise of those attacks as well as describing Hamas as heroes on their website constituted promoting and encouraging terrorism, Cleverly said.

The organisation also has a history of praising and celebrating attacks against Jewish people, he added.

A UK-based representative for the group did not immediately respond to an email seeking comment. On its website last month it described the call to ban the organisation as "a sign of the desperation".

Proscription means that it will be a criminal offence in Britain to belong to or promote the group, arrange its meetings, and carry its logo in public. Those breaching the rules could face up to 14 years in jail.

Cleverly has power to proscribe an organsation under British law if the group is believed to be "concerned in terrorism, and it is proportionate to do" according to the government's website.

Founded in 1953 and headquartered in Lebanon, Hizb ut-Tahrir operates in 32 countries including in Britain and other Western nations, with a long-term goal of establishing a caliphate ruled under Islamic law, the Home Office said.

It has been banned by Germany, Egypt, Bangladesh, Pakistan and several Central Asian and Arab nations.