In November 1925, at the time of the boundary commission crisis, a convention of the IRA withdrew the organization's loyalty to the pretender Dail fiireann in reaction to fears that some Sinn Feiners elected to the Free State Dail were softening in their abstentionist position. The fears of the dogmatic IRA were confirmed in March 1926 when de Valera withdrew from the Sinn Fein Party after it narrowly rejected his motion that consideration be given to having members attend Dail fiireann if the oath to the king was removed. On May 16 he started a new political party, Fianna Fail, which most of the politically successful members of Sinn Fein joined, leaving only a small rump in the original party.
The Free State felt so confident of the situation that it had already declared amnesty for offenses committed between December 6, 1922, and May 12, 1923, that is, from the conclusion of the treaty to the end of the civil war. It had earlier passed land legislation to complete the land purchase policies started before independence and had undertaken a public works hydroelectric scheme on the Shannon River. Its commitment to a nonpartisan civil service based on talent, including members of the pre-independence civil service, alienated a certain portion of its followers, who assumed public employment would be available for participants in the war of independence and treaty supporters. The presence in the ministry of people such as Patrick Hogan at Agriculture and Patrick McGilligan, who had replaced McGrath at Industry, and their deference to civil servants, especially those at the Department for Finance, where the minister was Ernest Blythe, resulted in a conservative or orthodox fiscal policy likely to alienate rank-and-file members of the electorate. The reduction of publicly provided old age pensions in 1924 epitomized the adherence to fiscal orthodoxy at the price of public favor, but the government justified the same as essential to draw purchasers of public bond issues and capital investors to an economy still being reconstructed from civil war damage.
Another issue in which O'Higgins took particular interest, since it was closely related to public order, was legislation regulating the sale of intoxicating liquor. His overall aim was to curb the excessive number of licensed premises in the country, a phenomenon stemming from the generosity of the judiciary of the old regime to supporters of the Irish Parliamentary Party, generosity extended as part of the "killing Home Rule with kindness" campaign. He also wished to standardize and shorten the hours in which such premises would be open. Vigorous opposition, especially from the vintners, the brewers, and the distillers, some of whom were important supporters of the government, required two separate pieces of legislation, one in 1924 setting set hours out of service and another in 1927, reducing the number of licenses with compensation and making further restrictions on hours of service.
A general election took place in June 1927. Cumann na nGaedheal had to contend with opposition not only from de Valera's new party, Fianna Fail, which was freshly invigorated with financial support from Irish America, and Sinn Fein, but also from the Farmers Party and the National League (a party led by William Redmond, the son of the late Irish Parliamentary Party leader) on the right and the Labour Party on the left. The failure of Cumann na nGaedheal to form a mass party organization and its tendency to rely on a "politics of deference," that is, endorsement by the professional classes, including the clergy, substantial shopkeepers, and larger farmers, as a stimulus to broader popular support, seriously handicapped it in a contest with the mixed nationalist-populist message of Fianna Fail. The results gave the government party only 47 seats out of 153, with Fianna Fail getting 44, Labour 22, the National League 8, Sinn Fein 5, and 16 independents. However, Fianna Fail's refusal to take the required oath to the king upon entry to the Dail kept them in their abstentionist position along with Sinn Fein. Accordingly, Cosgrave was again able to form a government, this time with only a plurality of seats.
A month later, on July 10, 1927, Kevin O'Higgins, who had assumed the portfolio of foreign minister as well as justice, was assassinated on his way to Sunday Mass by three IRA members acting on their own accord. They were never apprehended, but their identities were revealed posthumously more than a half century later. The government responded with public safety legislation allowing the suppression of certain periodicals, the outlawing of certain associations, and the use of military tribunals for certain offenses, as well as a constitutional amendment that would compel candidates for the Dail to declare their willingness to take the required oath.
Rather than abandon the seats to which they had been elected, de Valera and his Fianna Fail followers signed the required oath on August 11, but only after going through the theatrics of covering the document with a Bible and insisting that they were not taking an oath but only fulfilling a requirement for their signatures. Five days later, a vote of no confidence in the government, supported by Fianna Fail, Labour, and the National Party, failed to pass by one vote. A National Party member, John Jinks of Sligo, opted to absent himself, after being persuaded in the bar of the Shelbourne Hotel in Dublin that ex-army voters in Sligo would be displeased with his support for bringing de Valera to power. The Dail was dissolved and, in the subsequent election, Cumann na nGaedheal and Fianna Fail gained 62 and 57 seats, respectively, with a significant decline in the seats gained by other parties. Enough independents gave Cumann na nGaedheal a majority, giving it another four years in power to continue its work of state-building as well as giving Fianna Fail four more years to acquaint itself with the rudiments of constitutional politics.