prime ministerial hopeful said he wants to "refocus" the country's controversial anti-radicalism strategy onto Islamist extremism on Tuesday, saying this is Britain's "most significant terror threat".
The Conservative MP and former Chancellor of the Exchequer said that "no more important duty" exists for a prime minister than "keeping our country safe and our people safe".
Sunak also said he would expand the definition of extremism to encompass people with an "extreme hatred of Britain".
This would enable them to be referred to Prevent.
In May, The Guardian reported on leaked excerpts from a review of the controversial Prevent programme commissioned by the British government.
Despite repeated criticisms that the programme disproportionately targets Muslims, argued that Prevent has been overly focused on far-right extremism and should do more to combat the Islamist variety.
The Guardian cited "Sunak's team" as saying "vilification of the UK" would be added to the definition so that "those with an extreme hatred of our country that leads them to pose a risk to national security can be identified and diverted away from a destructive path".
supporters said the expanded definition wouldn't be legally binding or apply to mere disagreement with the government or its policies.
However, the pledge was criticised by ex-Prevent police lead Peter Fahy.
"What does vilification mean? Vilification would have to be carefully defined," The Guardian quoted him as saying.
Fahy also said "the widening of Prevent could damage its credibility and reputation", adding that "it makes it more about people's thoughts and opinions".
"It is straying into thought crimes and political opinions," he said.