Boris Johnson has revealed he plans to hand back his American passport.
The London mayor, who was born in New York, currently holds dual nationality, but has confirmed he intends to renounce his US citizenship, removing potential questions that could surround any bid to becoming Prime Minister.
"The reason I'm thinking I probably will want to make a change is that my commitment is, and always has been, to Britain," he told the Sunday Times during a week-long tour in the States.
"It's an accident of birth that has left me with this thing. I've got to find a way of sorting it out."
His dual nationality would not present a technical barrier to him becoming Prime Minister, constitutional experts believe, but it may lead to questions about his loyalities.
Mr Johnson - who is running for parliament in Uxbridge and South Ruislip - said he would approach US ambassador Matthew Barzun about the change. "It is a laborious business. They don't make it easy for you," he added.
American law requires all citizens to pay US taxes even if they live abroad. In January the Mayor settled a US tax bill.
Additional reporting by PA
