He was economic advisor to Taoiseach Enda Kenny from 2011, until he became a vice-president of the European Investment Bank between 2016 and 2020.
[12] He was credited with creating the slogan "keep the recovery going" used by Fine Gael in the 2016 Irish general election.
He negotiated with Fianna Fáil to establish a confidence and supply agreement which led to Fine Gael returning to government.
[15] The Irish government undertook a public competition and put forward McDowell as its nominee.
[15] His role encompassed oversight of the bank's treasury, economics and evaluation functions and institutional relations in some European and Asian countries.
[18] McDowell was one of two people, along with Mairead McGuinness, nominated by the Irish government on 4 September 2020 to replace Phil Hogan on the European Commission.