In the autumn of 1910 Childers resigned his post as Clerk of Petitions to leave himself free to join the Liberal Party, with its declared commitment to Home Rule, and in May 1912 he secured for himself the candidature in one of the parliamentary seats in the naval town of Devonport. As the well-known writer of "The Riddle of the Sands", with its implied support for an expanded Royal Navy, Childers could hardly fail to win the vote whenever the next election was called. The Liberal Party relied on Irish Home Rule MPs for its Commons majority. But in response to threats of civil war from the Ulster Unionists, the party began to entertain the idea of removing some or all of Ulster from a self-governed Ireland. Childers abandoned his candidacy and left the party.