In March 1938 the first election was held for the Seanad created by the Constitution. The Labour Party and Irish Congress of Trade Unions boycotted the election in protest at the inclusion of the tiny pro-Fianna Fáil Ballingarry Cottage Tenants' Association as a nominating body on the Labour Panel.[11] In consequence, de Valera as Taoiseach was required to add three names to the nominating bodies subpanel of the Labour Panel to reach the minimum of six candidates.[12] Hughes was one of these three.[12] Under the rules of the time, the 132 candidates from all ten subpanels were listed on a single ballot, with the 43 senators indirectly elected via single transferable vote by an electoral college comprising 330 public representatives.[11][13] Hughes was elected despite receiving zero first preferences, by receiving more transfers than one of the three Ballingarry Cottage Tenants' Association candidates.[12] As a senator, he voted for Pádraic Ó Máille as Leas-Cathaoirleach,[14] and spoke against a commission of inquiry on agriculture,[15] but in favour of a select committee on rural labourers.[16] He expressed little hope for vocational organisation but did not oppose de Valera's proposed commission on the topic.[17]
The 2nd Seanad was dissolved after the June 1938 Dáil election. Hughes did not stand in the August 1938 election for the 3rd Seanad, which was not subject to a Labour boycott.[11][3][18] He stood unsuccessfully on the Labour Panel in the 1943[19] and 1948[20] Seanad elections.
Hughes stood unsuccessfully in the 1945 election to Dublin City Council in the No. 2 local electoral area.[21] When his successful party running mate, J. J. Hannon, died in 1948,[22] Hughes was co-opted to fill the casual vacancy. He retained his seat at the local elections of 1950,[23]1955,[5]1960,[24] and 1967.[25] He was among those who nominated Charles Haughey to stand in the 1954 general election.[26] In 1958 he opposed the removal of the An Tóstal monument from O'Connell Bridge.[27] At the 1959 Fianna Fáil ardfheis he alleged people in Dublin were dying after failing the means test for public medical care; the Dublin Board of Assistance publicly asked him for more evidence.[28] In 1960 he was appointed to the council's Health Authority.[24] Hughes remained on the city council until Kevin Boland as Minister for Local Government dissolved it in 1969 for failing to strike an adequate rate.[29][30] The city was administered by an appointed commissioner, John Garvin.[31] Fianna Fáil councillors supported the dissolution, whereas the majority argued the Fianna Fáil government contributed proportionately less from the Central Fund to Dublin Health Authority than to other local authorities.[30][32]