The "toxic" Prevent counter-terrorism programme should be reviewed because it has lost credibility with Muslim communities, according to Green Party co-leader Caroline Lucas.
She said many Muslims believed the programme aimed at stopping people from being radicalised was an "attack on their group".
Ms Lucas also defended her opposition to mass online surveillance, saying the security services should focus on "targeted" measures.
The Green co-leader said she and colleague Baroness Jones had been labelled "domestic extremists" by police because of their campaigning and protesting activities, which was a waste of officers' time and resources.
Setting out her views on Prevent, she said: "Many in the Muslim community believe it's been an attack on their group in particular.
"We absolutely want there to be a mechanism whereby people can come to the state with concerns, but when it is perceived by the Muslim community itself as being a toxic Big Brother brand, then we need to look at it again."
Ms Lucas told BBC's Andrew Marr Show her party had opposed the so-called "snooper's charter" allowing mass monitoring of electronic communications because of civil liberties concerns and doubts over whether it could be effective, arguing "the bigger you make the haystack in which you're looking for the needle the harder it is to find it".
Calling for more targeted police and intelligence responses she added: "People like myself are on the domestic extremist list.
"People like peaceful environmentalists are on that list.
"How does that help if the police resources are being spent looking after people like myself or my colleague Jenny Jones rather than people that really pose a serious risk? And that's what we're saying."