In it, he seeks their support to remain leader of the Labour party.
"Thank you. Over the last weeks and months, we put everything into this campaign. It was always going to be a challenge to overturn this Government in less than a year, but I am immensely proud of the campaign we've fought together.
The thousands of you I have met over the last few weeks have reminded me how important it is to hope for a better future, and to believe in the great people of our country. The Labour Party is a movement of positive people -- I'm glad that our policies and strategy reflected that this election.
From the volunteering, to the fundraising, to the huge social media effort -- Labour supporters across the country have given it their all, and each day have reminded me why I love the Labour Party: that solidarity is something we live and breathe.
During this campaign we have all sensed the growing mood for change in New Zealand. We know New Zealanders share our values. But we clearly have more to do to earn their trust as a party and as a team.
Labour's challenge over the next three years is to show we are refreshed, united and ready to govern. We have already begun a path to renewal. We saw it in the energy in the campaign and the amazing turnout effort today.
But the challenge ahead of us is huge.
It means refreshing and modernizing.
It means building a machine that delivers Labour to the government benches so we can deliver a fairer, more decent society in three years' time.
This is a major programme of reform and it is appropriate that there is a firm mandate for this change.
That's why I will be seeking a new mandate from the party, the affiliates and the caucus by the end of the year.
I'll be in touch over the next few days with how we move on from here -- we're not done fighting for a better New Zealand.
But tonight, let's congratulate ourselves on remaining true to our values during a campaign well fought.
In solidarity, for a better New Zealand, David Cunliffe Labour Party Leader"