Martin McGuinness will tonight hit out at "sceptics and cynics" opposed to power-sharing between the DUP and Sinn Fein.
The Deputy First Minister is due to give a speech warning against the " misguided mindsets" which continue to underpin sectarianism.
In a keynote address to the British Irish Association, which is holding its annual conference in Cambridge, the former IRA leader is expected to stress that transition will not be easy.
And fresh from his talks in Finland with warring factions from Iraq - along with the DUP's Jeffrey Donaldson - Mr McGuinness will argue the positive work of the peace process can help the development of similar work in other parts of the world. The senior Sinn Fein negotiator will say: "The work we have undertaken since May 8 has been driven forward by the overwhelming mandate we have received from the ordinary people.
"Their voice and their votes have been the vital catalyst. It is the people, not the sceptics and the cynics, whose verdict on us matters."
But the central theme of the address is said to be hope: "Hope that we can move forward together to tackle the issues which historically divided our society; hope that we can defeat the scourges of sectarianism and racism (and) hope that we can continue to eradicate the conditions and misguided mindsets which unfortunately still exist, and which have produced intolerable incidents where we recently saw a new born baby's life put in danger when its parents' home was attacked."
Mr McGuinness will go on: "I know it will not be an overnight transition and there will be those who believe to transform our society is impossible. But we must continue to nurture that hope rather than the despair which is the alternative.
" Because it is difficult to change we should not fail in our determination to do so."
The Association is a registered educational charity, focused on conflict resolution.