Boris Johnson's 'inappropriate and disrespectful' remarks about Obama just cost him some major political support

The Mayor of London Boris Johnson claimed that US President Barack Obama harbours an "ancestral dislike of the British empire" because he is "part-Kenyan."

This remark has now cost him support from some key advocacy groups as well as a platform to speak at some events.

The London mayor's comments - which he made in an opinion piece for The Sun over the weekend in response to the President's London visit - have cost "Vote Leave" the support of the Africans for Britain organisation, which said it could no longer endorse a Brexit in light of Johnson's remarks.

The African advocacy group had previously backed Britain leaving the 28-nation bloc as it said doing so would encourage more trade with African and Caribbean nations. However, the group announced on Twitter on Saturday that it would no longer campaign for a Brexit because of Johnson's "alarming" remarks, and said it would be adopting a neutral position.

The group then posted a full statement on its Facebook page. It said it was "puzzled" by Johnson's remarks about Obama's ancestry, and said it feared the Brexit campaign was being taken over by a "radical wing," which is likely to try to "scapegoat" immigrants.

A society at King's College London has also uninvited the London mayor from speaking about the upcoming EU referendum, citing concerns about his "inappropriate and disrespectful" comments about the US President's Kenyan heritage.

The Think Tank club at the prestigious London university sent an email to Johnson, which said his remarks didn't reflect the "true greatness of the United Kingdom" and the "tolerance" and "respect" it has for all.

Read the email in full, below:

Dear Mr Johnson,

Given your inappropriate comments and inferences towards President Obama's Kenyan heritage, of which he is rightly proud, and your general tone of disrespect over the past few days in relation to the President of the United States of America, we are now formally withdrawing your invitation at Kings College London.

We are looking forward to providing a forum for both sides in the EU Referendum Debate to argue their point of view without fear or favour. The level of discourse over the past few days does not meet the bar we set for these events nor do we feel does it help the British people in making the most momentous decision of our lifetime. Furthermore we believe it does not reflect the true greatness of the United Kingdom, a land of tolerance, respect and fair play towards all. 

Johnson became one of the Leave campaign's most high-profile advocate in February when he announced he would be campaigning for a Brexit. He received support from fellow Tory and former cabinet minister Iain Duncan Smith on Monday, who said Johnson's point was "correct" about the President and described accusations of racism against him as "absurd."

Obama visited London last week to persuade British people to vote to remain in the EU on June 23. He said in a BBC interview that if Britain left the EU, it could face a decade-long wait to strike trade deals with the US if it were to leave the 28-nation bloc.

Business Insider has contacted the Vote Leave campaign and the mayoral office for comment.