In late 2005, Brady and his brother Royston, a former Lord Mayor of Dublin and unsuccessful candidate for the European Parliament, were both reported to be in contention for a Fianna Fáil nomination in the Dublin Central constituency. Although Dublin Central was the constituency of the then Taoiseach Bertie Ahern and was considered a strong Fianna Fáil constituency there was stiff competition from other parties. In 2002 the second Fianna Fáil TD Dermot Fitzpatrick had been elected in 2002 with a narrow margin of just 79 votes over the Sinn Féin candidate Nicky Kehoe. The rivalry between the brothers led to a public call from a third brother, Fulton Brady, to "put an end to it". Royston was not one of the four contenders nominated for at the selection conference in March 2006, when Cyprian Brady and Councillor Mary Fitzpatrick were selected as Ahern's two running-mates. Fitzpatrick was the daughter of the outgoing TD Dermot Fitzpatrick. At the 2007 general election, held under Ireland's single transferable vote system, Brady polled just 939 first preference votes in the first count. However he was elected on the fourth count, due in large part to a pre-arranged electoral strategy seeing large transfers from his running mate, the Taoiseach Bertie Ahern, and became only the second ever TD to be elected with less than 1,000 first-preference votes. His election became the subject of a public interest, covered in national newspapers and on the RTÉ Radio 1news programmeDrivetime and on the weekly Documentary on One which had been covering the campaigns of the three female candidates in the constituency. Mary Fitzpatrick, daughter of the outgoing Fianna Fáil TD and the third Fianna Fáil candidate in the 4-seat constituency, received 1,725 first-preference votes and 1,362. On the night before polling day, 24 May 2007, Fitzpatrick distributed leaflets to households asking people to vote for her as their first preference. In the early hours of the following morning, a letter had been hand-delivered from Ahern's office to 30,000 voters in the constituency, urging them give their first preference to the Taoiseach and their second to Brady. Since Ahern was expected to be elected with a large surplus, and the overall Fianna Fáil vote was likely to be large enough to elect two candidates, the destination of the Taoiseach's transfers would determine whether Brady or Fitzpatrick won the second Fianna Fáil seat in Dublin Central. After Ahern's transfers secured Brady's election, Fitzpatrick complained that "I didn't think they'd go out to completely undermine me and shaft me." Ahern's election agentChris Wall blamed Fitzpatrick, saying "She was asked not to do this sort of thing. Having then done it, she therefore effectively set in train a motion she wasn't going to be able to stop." Brady said "An election is an election and not everybody can win", adding "Mary is a colleague of mine and she is a very good councillor. It's not really fair for Mary to be blaming anybody".
In January 2011, he was selected as a Fianna Fáil candidate in Dublin Central for the 2011 general election along with Mary Fitzpatrick. Former Taoiseach Bertie Ahern said his loyalties this time would be with the sitting TD, and there was no hope of Fianna Fáil winning two seats in the constituency. He lost his seat having received 1,637 votes.
