Producers recently revealed that one of the soap's cast will die during a live episode airing later this month. The scenes mark the 40th anniversary of the show, and 58-year-old Halliwell - who has played farmer Zak for 18 years - hopes that he will not be the one to go.
"I'd be devastated," he told PA when considering the possibility that Zak may be killed off.
"You've got financial commitments, and you get to a certain age where you don't want to go back to square one. Personally I'd be devastated if they killed Zak."
Fellow cast member Tony Audenshaw - who has played barman Bob Hope for 12 years - revealed that he is less worried about being written out of the show.
"It's fine," he said. "It's all part of being in a soap. I only came for three months, so I'm just glad I'm here now. No-one owes us a living."
Both Halliwell and Audenshaw will appear in the live episode, but neither has been shown the full script in an effort to keep the plot top secret.
"We're only shown bits so it doesn't leak out," Halliwell explained.
John Middleton, who plays vicar Ashley Thomas, revealed that the whole cast has been feeling nervous about the upcoming scenes.
He said: "We've all admitted we're having the classic actor's nightmare of waking up... on stage. You don't know what the play is, no-one's given you a clue, and you can't get across to the prompter's corner."
Emmerdale launches its 40th anniversary celebrations on Monday, October 15.