In 1926, Ryan was among the Sinn Féin TDs who followed leader
Éamon de Valera out of the party to found
Fianna Fáil. They entered the Dáil in 1927 and spent five years on the opposition benches. Ryan was given the task of implementing the following policies: imports of wheat, sugar and other agricultural produce were restricted; farmers were given a guaranteed price for wheat; farmers were forced to use home-produced grain in animal feed and bakers had to use a certain percentage of Irish flour in their bread; and the sugar beet industry was expanded with the opening of new factories. While these policies saw increases in sugar-beet and wheat production, the small farmers of
Munster and
Connacht gained little, while the large farmers were the real beneficiaries. Ryan faced severe criticism over the
Economic War with
Britain: serious harm was done to the cattle trade, Ireland's main export earner. The government tried to compensate by giving bounties equal to the British duties, however, these had to be paid for by the taxpayer. The economic war ended in 1938 with the signing of the
Anglo-Irish Trade Agreement between both governments, after a series of talks in London between the British Prime Minister
Neville Chamberlain, de Valera, Ryan and
Seán Lemass. During
World War II, self-sufficiency in food became essential. The
Department of Agriculture ordered every farmer to till one-eighth of his land. This was raised to three-eighths in 1944. In spite of strict rationing and severe shortages, basic foodstuffs remained available. At the war's end, farmers discontent emerged once again. A new political party,
Clann na Talmhan, had been established in the late 1930s to represent the interests of smaller farmers in the west of Ireland. Also, much of the country's land had become exhausted due to increased wartime productivity and a shortage of fertilisers. As Minister for Agriculture, Ryan was also involved the handover of
Johnstown Castle estate, County Wexford in 1945. The facility became an important soil research centre initially under the Department for Agriculture and later as An Foras Talúntais (now
Teagasc).
Minister for Health and Social Welfare In 1947, after spending fifteen years as Minister for Agriculture, Ryan was appointed to the newly created positions of
Minister for Health and
Minister for Social Welfare. The minister brought the draft Health Bill to the cabinet's attention later that year. This legislation proposed to modernise the health service into two aspects – mother and child welfare and infectious diseases. De Valera was anxious about accepting these measures as government policy due to opposition from the Catholic Church. In fact, much of the legislation was enacted by
Noel Browne, Ryan's successor as Minister from 1948 to 1951. Following Fianna Fáil's return to power at the
1951 general election, Ryan returned as Minister for Health and Social Welfare. During his second period in office he clashed with the Church once again over the implementation of the remaining aspects of the
Mother and Child Scheme. Following negotiations with the hierarchy, adjustments on such issues as means testing and medical inspections were made and the legislation was passed in the Dáil. Following the
1954 general election, Fianna Fáil lost power and Ryan moved to the backbenches once again.
Minister for Finance Following the
1957 general election, Fianna Fáil were back in office and de Valera's cabinet had a new look to it. In a clear message that there would be a change to economic policy Ryan, a close ally of
Seán Lemass, was appointed
Minister for Finance, replacing the conservative
Seán MacEntee. The first sign of a new economic approach came in 1958, when Ryan brought the First Programme for Economic Development to the cabinet table. This plan, the brainchild of
T. K. Whitaker, recognised that Ireland would have to move away from self-sufficiency towards free trade. It also proposed that foreign firms should be given grants and tax breaks to set up in Ireland. When Seán Lemass succeeded de Valera as
Taoiseach in 1959, Ryan was re-appointed as Minister for Finance. Lemass wanted to reward him for his loyalty by also naming him
Tánaiste; however, the new leader felt obliged to appoint Seán MacEntee, one of the party elders to the position. Ryan continued to implement the First Programme throughout the early 1960s, achieving a record growth rate of 4 per cent by 1963. That year an even more ambitious Second Programme was introduced; however, it overreached and had to be abandoned. In spite of this, the annual growth rate averaged five per cent, the highest achieved since independence. ==Retirement and death==