- This story was corrected on 31 July 2013; please see final paragraph
Employees on such contracts typically have no guarantee of regular work but cannot work elsewhere and do not receive holiday or sick pay. Tate Enterprises however said its employees are able to take other work without restrictions and it does pay holiday and sick leave.
The unions Unite and Unison have called for the practice to be made illegal, and Vince Cable, the business secretary, has ordered a review of the practice.
Tate Enterprises is a wholly-owned subsidiary of the charity and operates its publishing, catering and retail activities. All profits are Gift-Aided back to the charity.
"Tate Enterprises and Tate Catering employs staff on permanent zero hours contracts across Tate sites," the charity said in a statement. "Zero hours contracts enable Tate to manage the changes in staffing levels that are inherent in retail and catering operations and allow employees on these contracts the flexibility to agree mutually beneficial working hours."
The Tate Gallery does not employ people on zero-hours contracts, it said.
- The story originally said that workers on zero-hours contracts are not able to work elsewhere.