Thorne was one of more than 100 influential disabled people to sign an open letter to Prime Minister Keir Starmer, which said of the cuts: "This is not reform; it is cruelty by policy."
The letter, published as part of the new #TakeThePIP campaign, was signed by actors Liz Carr and Doctor Who star Ruth Madeley, as well as comedians Rosie Jones and 2018's Britain's Got Talent winner Lee Ridley, otherwise known as Lost Voice Guy.
They say the changes to the way Pip will be awarded is a "radical departure from the current system".
Currently those receiving the benefit must score 12 points across various activities in the assessment, but from 2026 four of the 12 points must come from one single activity for the applicant to receive the highest rate.
The signatories said these changes mean those who "can't wash below the waist, for example, could now not qualify and lose vital benefits",
"For us, Pip is not a benefit - it is access to life. Without it, people are left housebound and isolated."