A spokesperson for the Information Commissioner’s Office said:
“The Electoral Commission has contacted us regarding this incident and we are currently making enquiries. We recognise this news may cause alarm to those who are worried they may be affected and we want to reassure the public that we are investigating as a matter of urgency.
“In the meantime, if anyone is concerned about how their data has been handled, they should get in touch with the ICO or check our website for advice and support.”