Former minister Paschal Donohoe is due to start his new job at the World Bank in Washington DC on Monday.
The Fine Gael TD announced his resignation from the Cabinet yesterday, after more than 14 years in the Dáil.
Gerry Hutch is among the names rumoured to contest his vacant seat, but Mr Donohoe says he's confident the people of Dublin Central will elect the right candidate in the by-election.
Longford senator Paraic Brady paid tribute to his Fine Gael colleague in the Seanad: