In June 1973, elections were held to a new devolved parliament, the Northern Ireland Assembly. The elections split the UUP. Faulkner became chief executive in a power-sharing executive with the SDLP and the centre-ground Alliance Party, a political alliance cemented at the Sunningdale Conference that year. However, the prominence in the Sunningdale Agreement of the cross-border Council of Ireland suggested that Faulkner had strayed too far ahead of his party. A section of the party had previously broken away to form the Vanguard Progressive Unionist Party, which contested the elections in opposition to the UUP.