Further affected stores are Bournemouth, Stockton, The Fort, Scunthorpe ,Narborough Road, Grantham, Redditch, Skegness, Sutton, Coldfield, Orpington, Edmonton Green, Llanelli, Merthyr Tydfil and Cleethorpes.
Each store will have a 30-day consultation period while permanent recruitment in the vicinity of each site will freeze.
“It’s yet another nail in the High Street’s coffin and GMB calls on councils and landlords to review commercial leases and offer lower rents.
“Empty high streets and shopping centres are in no one’s interest and but with 400 shops a week closing, this is inevitable - unless the costs of premises can be reduced.
“GMB will now meet with Wilko members to discuss our next steps.”
Jerome Saint-Marc, Wilko’s chief executive said: “Our history is steeped in serving our customers and communities going back to 1930 but there’s no denying the way people shop with us and where they want to shop with us is changing.
“As a business we’re evolving and this includes working with landlords for more favourable terms, as well as looking at locations and store formats.
“We’ll continue to pull together to make our business better to secure the future of over 16,000 team members.
“We’ll be doing everything we can to support our affected team members who will be offered any available positions in nearby stores.
“We apologise to those communities where stores are closing but will continue to offer them everything they need in nearby stores or via wilko.com.”
Wilko said 11 of the 15 stores have an alternative Wilko within five miles.
The retailer has 414 stores across the UK.