(Reuters) -Walgreens Boots Alliance will close nearly all of its stores and pharmacies on Thanksgiving Day for the first time in the chain's history, amid pushback from pharmacists and technicians over poor work conditions and under-staffing.

Peer CVS Health also said it plans to shut all of its non-24-hour pharmacy locations early next Thursday, while Rite Aid said its pharmacies will be closed but retail stores will remain open.

All Rite Aid stores will be closed on Christmas, it added.

Walgreens, the second-largest U.S. pharmacy chain, will close most of its over 8,700 stores on Thanksgiving to give staff "time with their loved ones", it said on Thursday.

This year marks a change in pace for these companies as pharmacies and grocery stores typically remain open with adjusted hours on Thanksgiving, unlike big-box stores such as Walmart and Target that are shut.

"We have consistently heard from our team members — who are the face of Walgreens — that time off is a meaningful way for us to demonstrate we value them," said Tracey Brown, president of Walgreens Retail and chief customer officer.

However, nearly all of Walgreens' 700 24-hour locations will remain open on Thanksgiving, along with certain distribution centers and other sites including supply chain and centralized teams.

The announcements come at a time when many pharmacists and technicians in the U.S. have been trying to unionize with support from the IAM Healthcare union.

Some employees at CVS and Walgreens' U.S. pharmacies had launched a three-day walkout from Oct. 30 to push the companies to improve working conditions and add more staff to their stores.

However, both companies said the work action had minimal impact on their operations, with most stores remaining open.

(Reporting by Leroy Leo and Bhanvi Satija in Bengaluru; Editing by Devika Syamnath)