National's last-ditch attempt to cash in on John Key

John Key
John Key made his shock resignation announcement last December (AAP / file)

John Key has been keeping a very low profile ever since he resigned as Prime Minister - but he's popped back up again in a clear last-ditch attempt from the National Party to cash in on his popularity.

As part of a farewell message to National Party members, Mr Key urges members to donate to National's 2017 campaign.

"If you are as committed as I am to seeing New Zealand succeed...I would encourage you to make a contribution," the message reads.

national funding election campaign email john key

Mr Key made his shock resignation announcement in December last year, wanting to leave the job while still on top.

The Helensville MP said he would stay on long enough in Parliament so as not to trigger a by-election in an election year.

There doesn't have to be a by-election if the general election is held within six months of a seat being vacated. Election Day is September 23.

Mr Key will give his valedictory speech on March 22, with his resignation effective from April 14.