Tension between President Mokgweetsi Masisi and his predecessor former President Ian Khama deepened further last week when the latter declined an invitation to fly on Presidential jet OK1 to London. Both Masisi and Khama were invited to the two-day conference on Illegal Wildlife Trade in London which ended on Thursday. Sources at Office of the President (OP) told The Patriot on Sunday during the week that Masisi extended an invitation to Khama to fly with him on OK1, but he turned down the offer. Instead, Khama used commercial flights to make the trip to London on Tuesday, a development that has not sat well with Masisi. Ahead of the London trip, OP is said to have written a letter to Khama's office inviting him to fly “at His Excellency’s invitation” to the conference. In response Khama is said to have told OP that he had already made his own travel arrangements to attend the conference. Efforts to convince him to accompany President Masisi are said to have hit a snag as he told them flatly that he did not want to be embarrassed by the Permanent Secretary to the President Carter Morupisi at the airport telling him he can no…