Security minister Dan Jarvis told Times Radio the government would fast-track legislation that would allow the prosecution of people acting as a proxy of a state-sponsored group under Britain's National Security Act.
The government said the new powers would mean proxies could be dealt with in the same way as foreign intelligence services.
The plans were announced after Wednesday's stabbings, which follow a spate of recent attacks, many involving arson, on Jewish targets in London.
In October 2025, two people and an attacker were killed after a man drove at a synagogue in the northern English city of Manchester.
Britain's independent reviewer of terrorism legislation, Jonathan Hall, told the BBC the attacks had become "the biggest national security emergency" since 2017, when there were a string of high-profile attacks.
The attacks have occurred amid warnings from security officials that Iran has sought to use criminal proxies to carry out hostile activity.
Police said after an arson attack at a synagogue this month that they were investigating possible Iranian links to the incidents.
A pro-Iranian government group has said it was responsible.
Jarvis also said on Thursday that there would be an additional Stg25 million ($A47 million) to protect the Jewish community, which the government said brings the total funding this year to Stg58 million.
