Boris Johnson had no idea about the clause in Transport for London's contract with the Emirates not to criticise the Dubai government or do deals concerning the Thames cable car with Israel, his office has admitted.
And the Mayor called on TfL boss Sir Peter Hendy to immediately renegotiate the contract, which Emirates have agreed to do.
The Huffington Post reported on Tuesday that the Mayor had effectively gagged himself and TfL from criticising the Emirati government or Royal Family in connection with the Emirates Airline, and agreed to abide by UAE foreign policy when entering into contracts and partnerships relating to the cable car while the deal is in place.
That meant a ban on deals with Israel, the only country with which the UAE does not have diplomatic relations.
The Mayor's official spokesman told HuffPost UK both clauses were being drafted.
"The Mayor was unaware of the clause in question, the details having been drawn up by TfL officials," she said.
"When he was told about the clause yesterday he asked Sir Peter Hendy to speak to Emirates. Following those discussions Emirates agreed to remove the clause and re-work the wording.
"The Mayor is pleased Emirates has moved quickly to clarify the situation."
Emirates said they were happy to comply with the Mayor's request.
“The clause in the Emirates contract with TfL was put in place to protect the commercial interests of the Emirates brand. The clause was not intended to discriminate against any particular person, religion or country," a spokesman told HuffPost UK, referring to the ban on deals with Israel.
"Given the misinterpretation of this clause Emirates has agreed with TfL to remove it from the contract. Emirates, a global multicultural, multimedia company, does not discriminate against passengers of any race, people or religion.
"Emirates is proud to employ people from over 160 nationalities and connect people from all backgrounds across our international network.”
On Wednesday, TfL told HuffPost UK the contract does not ban expressions of opinion and said it was standard for a sponsor to expect that it would not sell the cable car on to someone else that contradicts the commercial interests of Emirates - including any Israeli company.
But the transport authority has since revised its opinion, telling HuffPost UK on Wednesday morning they would soon publish the revised wording of the contract.
Danny Price, TfL’s Head of the Emirates Air Line, said: "We have agreed with Emirates that this clause should be removed from the contract.
"The intention behind it was always to give Emirates the option to withdraw their sponsorship should we sell the Emirates Air Line to someone else, something which is common in such contracts.
"We will work on, and publish, alternative wording to express this in these simple terms. Moreover, we cannot foresee any circumstances in which we would sell the Emirates Air Line."
Johnson came under fire from Labour Assembly members for his lack of attention to detail.
Labour London Assembly Member Andrew Dismore said: “TfL clearly have not read their own contract.
“It is clear that if TfL wished to bring an Israeli company into the operation or monitoring of the performance of the cable car, it would be in breach of this contract.
“It is clear the contract is aimed at boycotting Israeli businesses. If it is not, why do they have these terms in the contract at all?
“It is fatuous of TfL to suggest that it is to exclude an organisation “that cuts across the commercial interests of a main sponsor” and that "this is standard practice”.
“If that were the case, the “conflicting person” definition would be set out in terms of commercial conflicting interests, not in terms of diplomatic interests by referring to countries with which the UAE does not maintain diplomatic relations.
“This cannot by any stretch be seen as normal standard business practice.”
The £63m Emirates Air Line cable car travels across the Thames from North Greenwich to the Royal Docks.
The former Mayor of London, Ken Livingstone, told HuffPost UK earlier he would never have agreed to such a clause.
"Boris just doesn't do detail. He was very busy writing a book about the history of London at the time," he said.