Chas is about to begin a secret relationship with Cameron Murray (Dominic Power), who is the partner of her niece Debbie (Charley Webb).
Pargeter, discussing her Emmerdale future, told The Mirror: "I always worry, no matter what Chas is doing. Our job is so precarious, and you don't know when you might fall out of favour and it's all change.
"Don't get me wrong, it's been a great year. Now Chas has The Woolpack, it feels like I'm part of the furniture. But still, you don't know what's round the corner. I'm just one of these people who's always been a bit of a worrier.
"I am a bit nervous about what people are going to say about Chas and Cameron too. Chas has never really been bad before, people have always liked her and the comments I get are usually 'go on love', but that all could change with this storyline.
"I'm hoping the fans won't be too hard on her and get too cross. Who knows? I might start getting bashed up in the street, attacked by little old ladies and their handbags!"
Pargeter also confirmed that Chas and Cameron's affair plotline is likely to run for some time.
"It's Emmerdale's 40th anniversary, so there are going to be some amazing storylines," she explained. "Maybe we'll be part of that.
"The chemistry between the two characters is so intense it will keep drawing them back together. It is certainly not going to be a flash in the pan between them."
Emmerdale airs weeknights on ITV1.
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Watch a preview of tonight's (April 12) Emmerdale double bill in the video below: