There was a strong debate about the British Security Services to investigate the Muslim Brotherhood and to study whether it is a terrorist group or not, and whether its members in Britain are involved in terrorist attacks in Egypt.
Some people believe that the Britain government is taking the investigations seriously, while others believe it's not. The other team believes it is but a game played by Britain to deny its support to the terrorist group that documents prove it was supported by Britain since its very beginning.
In fact, Britian has already named Ansar Beit al-Maqdis a terrorist group which is known as a branch or military wing of the Muslim Brotherhood, just like Hamas and al-Qaeda.
However al-Qaeda was funded and supported by America, it is considered, by America itself, the most dangerous terrorist organization. This may support the idea that Britain may consider the Muslim Brotherhood a terrorist organization after it had supported it in the past.
Such fact may be supported by the information presented by the Egyptian intelligence to the Britain intelligence proving the Muslim Brotherhood had planned some terrorist group in Britain.