The plan, which was made public on Wednesday by the British Home Secretary Suella Braverman, would make it unlawful to support or be a member of the armed group or use its logo.
The proscription order, which is made possible by the anti-terrorism laws currently in effect, also gives the government the authority to seize assets and property that are thought to be connected to the organisation.
The ruling carries a maximum 14-year prison sentence and fines for violations.
“They are terrorists, plain and simple,” Braverman said in a statement published on Wednesday. “Wagner has been involved in looting, torture and barbarous murders. Its operations in Ukraine, the Middle East and Africa are a threat to global security.”
Wagner was largely regarded as a Putin-aligned proxy army, allowing Moscow to advance its objectives in Syria, Libya, and other African nations while maintaining a veneer of plausible denial.
That is, until the Russian invasion of Ukraine, when Wagner suddenly became a field force fighting alongside the Russian army.
Wagner commander Yevgeny Prigozhin openly criticised the Russian military’s incapacity to supply his soldiers with weapons and supplies after a year of combat in Ukraine.
When Wagner soldiers briefly took over Rostov-on-Don in June, tensions reached a boiling point.
Despite assurances that Moscow and Wagner had reconciled their differences, Prigozhin and much of Wagner’s command were killed in an air crash in August widely suspected to have been orchestrated by the Kremlin.
While the group remains active, it is expected that the Kremlin will take a more hands-on approach with the organisation moving forward.
The move by Braverman adds to the UK’s existing sanctions against Moscow, which include asset freezes targeting key allies of Putin, as well as restrictions on doing business with Russia.
The first mention of Wagner was made in 2014, with the Russian annexation of Crimea from Ukraine, although the group also swiftly established a presence there.
It participated in the conquest of oil fields from various armed opposition organisations against the Assad administration, including the Islamic State and the US-allied Syrian Democratic soldiers, and assisted in the training of government soldiers.
When those resources were successfully captured, Wagner’s many shell firms would receive substantial contracts for the oil and gas extracted, and the money would be sent back to Moscow.
In both Sudan and Libya, where it is linked with rebel general Mohamed Hamdan Dagalo, also known as Khalifa Haftar, the mercenary force has adopted the same strategy.
Both Haftar and Hemeti are vying for control of their respective countries and are in charge of paramilitaries that have been accused of human rights violations.
In the Sahel region of Africa and further south, Wagner has worked alongside local militias to set up and protect mining operations, with the resulting profits and resources channelled back to Russia.
The organisation is accused of pilfering billions of dollars worth of gold in its operations and massacring hundreds of civilians in the Central African Republic.