Salma, who is currently finishing her Ph.D. in Britain, refuses to disclose the number of people involved in the London office, saying only, "There is a hierarchical organization; we are organized and very structured, and very well informed."
"We have always been here, for a couple of decades now," she says. "The Brotherhood is an international organization; it is not only in Egypt."
The Brotherhood clearly has a London set stretching back generations. Its leaders began fleeing to Europe in the 1950s, when then President Gamal Abdel Nasser staged a crackdown on the organization, says Khalil al-Anani, a senior fellow at the Middle East Institute in Washington.
Anani believes that Egypt is witnessing a repeat of Nasser's 1954 crackdown on the Brotherhood, which could cause a fresh wave of Islamist members to move back to Britain. "After Monday's ruling they will be more vulnerable."
Khairat al-Shater, a leading Brotherhood member who is currently in prison and was seen by many as the power behind Morsy's throne, was in exile in London in the mid-1980s together with Essam al-Haddad, a presidential aide who was detained in mid-September by security forces of Egypt's military rulers.
Essam's son, Abdullah al-Haddad, is now an active member of the Brotherhood's London wing. The Haddads are not the only family with powerful links to Brotherhood networks in London and Cairo: The brother of Salma, the spokesperson, was part of Morsy's presidential team and is currently being held in an undisclosed location.
Even from the relative safety of London, members of the British Muslim Brotherhood operate with caution. The Egyptian authorities are reportedly keeping a watchful eye on the Islamists' activities in the British capital.
"We cannot be quoted by name anymore; it is huge security problem even here," Salma says. "We all have families in Egypt, so the security issues are personal -- there are family pressures. I do not wish any of my family back in Egypt to be affected by my activism."
The Egyptian expatriate community in London is not all pro-Brotherhood, Salma admits. There have been counterprotests supporting the military in London, and most Egyptians living in Britain actually preferred Hosni Mubarak's former prime minister, Ahmed Shafiq, in the presidential election. "The majority didn't vote Morsy," says Salma, referring to London's ex-pats.
But with Brotherhood supporters fleeing to London as the government continues its crackdown, the number of Morsy supporters may be catching up with their rivals. Salma maintains that she and fellow Brotherhood activists will eventually return to Egypt -- but as the crackdown continues to mount, that moment seems far off.
"Hundreds of Egyptians like me thought we could get a better education in London [and] then go back to build a democratic Egypt," she says. "But [the government] may keep me away from my family."