Cape Town - Nigerian President Muhammadu Buhari's "powerful" aides are reportedly denying ministers, family and friends access to the 74-year-old, who is on an extended medical vacation in London.According to Punch, at least four aides were in control of who got access to Buhari. The four were said to be the president's nephew Mamman Daura, senior special assistant to the president on domestic affairs Sarki Aba, Buhari's Chief of Staff Abba Kyari, and personal assistant to the president Tunde Sabiu.Anyone who wanted to telephone or see the president had to first seek permission from one of the four aides, it was alleged. This, however, did not apply to the acting president Yemi Osinbajo and First Lady Aisha Buhari. The report said that the First Lady was not happy about the arrangement and was, therefore, not staying with her husband as was supposed to be the case. She was said to be travelling between Nigeria and the UK on a regularly bases."The First Lady is not with him [Buhari] permanently in London, which should normally not be the case. She has had a few clashes with the cabal and she is not happy that they are also firmly in control in London. That’s why she goes and comes. She is not happy with the atmosphere over there," an unidentified source was quoted as saying.Surprise phone call Aisha's relationship with the president's aides has not always been cordial.In October last year, Aisha granted a highly controversial interview to BBC, in which she alleged that a "cabal" had hijacked her husband’s government.At the time, she claimed that she "might be forced not to support her husband's re-election in the next elections". She also said that half of the people Buhari had elected into government post elections were unknown to him. Meanwhile, sources close to the president said that the "cabal" that the First Lady referred to in the interview were the four aides. The sources said that the four had so barred a number of people, including ministers, personal friends and some family members, from having access to the west African country's leader. This came just less than a week after Buhari reportedly made a surprise phone call to the governor of the northern state of Kano. Buhari’s conversation with the governor was put on speakerphone, with the phone placed next to the mic to allow those at a prayer session to follow the call.