Butler announced on 6 March 1963 that he was going to convene a conference to decide the Federation's future. It would be impossible (or at least very difficult) for the UK to dissolve the union without Southern Rhodesia's co-operation as the latter, being self-governing, had been co-signatory to the Federal agreement in 1953. According to Smith, Field, Dupont and other RF politicians, Butler made several oral independence guarantees to ensure Southern Rhodesia's attendance and support at the conference, but repeatedly refused to give anything on paper. Field and Smith claimed that Butler justified this to them the day before the conference began by saying that binding Whitehall to a document rather than his word would be against the Commonwealth's "spirit of trust"—an argument that Field eventually accepted. "Let's remember the trust you emphasised," Smith warned, according to Field's account wagging his finger at Butler; "if you break that you will live to regret it." No minutes were made of this meeting. Butler denied afterwards that he had ever made such a promise. Southern Rhodesia attended the conference, held at the Victoria Falls Hotel over a week starting from 28 June 1963, and among other things it was agreed to formally liquidate the Federation at the end of 1963.