SWIFT is an organization that carries messages back and forth between banks. If it does not disconnect access from Iranian banks after November, when the U.S. re-imposes banking sanctions, European nations will be able to sidestep those sanctions by enabling deals between European banks and sanctioned Iranian banks through SWIFT.

The move by the UK government draws a sharp contrast with the position taken by opposition leader Jeremy Corbyn, who in 2009, during a meeting in parliament, referred to members of Hezbollah and Hamas as “friends.”