The resignation of Major Chichester-Clark over the franchise issue and the continued division within the parliamentary party finally led Captain O'Neill to resign. Brian Faulkner and Major James Chichester-Clark, both former ministers under O'Neill, were nominated for the leadership. Chichester-Clark won by one vote and became both prime minister and leader of the Unionist Party.
Here is a selection of RTÉ television and radio coverage of Captain Terence O'Neill's last days as premier and the election of Chichester-Clark.
The accompanying image is taken from RTÉ News footage of Major Chichester-Clark giving his first interview to the press following his election as leader on 1 May, 1969.
Following the local government franchise vote, Captain O'Neill's position as leader of his party and Prime Minister is looking increasingly weak.
Ronnie Turner reports on reaction to the news that Captain Terence O'Neill is to step down as leader of the Unionist Party.
John Hume does not see that the replacing of Captain Terence O'Neill will offer any hope to the civil rights movement.
Brian Faulkner and Major Chichester-Clark are both running for leader of the Unionist Party following the resignation of Captain Terence O'Neill.
Brian Faulkner talks about how he would lessen tension in Northern Ireland if elected prime minister and his intention to carry on the reform measures commenced under Captain Terence O'Neill.
Chief Whip of the Unionist Party and Chairman of the selection meeting, Roy Bradford, announces the leadership result, which sees Major Chichester-Clark defeat Brian Faulkner by a single vote.
Following his election victory, Major Chichester-Clark answers questions from a large media gathering.
Following the leadership election, Captain Terence O'Neill leaves Stormont but says he will be staying in politics.
William Craig says he will give his full support to the new leader and does not rule out a place in the cabinet, should it be offered.
Barry Linnane seeks the views of Catholics and Protestants on the election of their new Prime Minister.