The 61,000sq ft store will create up to 130 jobs and will feature M&S Clothing and Homeware and include a large Foodhall.
Local residents are invited to grab a glass of fizz and celebrate the opening at 10am on Thursday when store manager, James Harden, and his team of colleagues will cut the ribbon and welcome customers into the store for the first time.
The first 50 customers through the doors on Thursday will be given a special M&S goody bag.
Customers will also be in with a chance to win a share of M&S gift cards and a range of exciting prizes.
Throughout the day there will be in-store sampling of the very best M&S food products and a chance to ‘ask the experts’ in various departments around the store.
For shoppers looking to enjoy M&S’s innovative food, the new 9,000sqft Foodhall will offer the full range of M&S food with over 6,000 products available, including the latest innovations in health and convenience food. The new Foodhall will also feature the very latest in M&S Autumn food range.
For those looking for somewhere to enjoy a coffee and cake or a catch up with friends over lunch the store will feature a 130-seater Café.
Manager James said: “We’re excited about bringing the biggest M&S store for 2016 to Biggleswade and I can’t wait to hear customers’ reactions on the extensive offer we will be unveiling.
“The team and I are looking forward to welcoming customers to the opening on September 29.”