Tag #Uk Parliament Security

What specific security vulnerabilities were exposed by the presence of convicted Russian spies at a 2016 parliamentary event?

In May 2016, three Bulgarian spies—Orlin Roussev, Biser Dzhambazov, and Katrin Ivanova—attended a Brexit debate in the Palace of Westminster. Photographs confirm their presence alongside representatives from various European political parties. This event was sponsored by Baroness Brown of Silvertown, who claims no memory of their attendance.