In August 1899 when it became clear that the Labour Party could be manoeuvred into bringing down the Reid Government, Barton resigned as leader of the opposition, as he was unacceptable to Labour, and William Lyne took his place. He refused an offer to become Attorney-General again. He resigned from Parliament in February 1900 so that he could travel to London with Alfred Deakin and Charles Kingston to explain the federation bill to the British Government. Around the same time on 15 January 1900 Barton published a 28-page "United Australia" magazine to disseminate an informative narrative for the propositions of a future Federal Government that he hoped to lead. The British Government was adamant in its opposition to the abolition of appeals to the Privy Council as incorporated in the draft constitution; eventually, Barton agreed that constitutional ("inter se") matters would be finalised in the High Court, but other matters could be appealed to the Privy Council. Edmund served as a Justice of the High Court for 16 years.