Clutha-Southland MP Hamish Walker is the second National MP in that seat to quit in his first term.
His predecessor, Todd Barclay, took the seat after former holder Bill English went list-only. But Barclay was persuaded to step down early after a staffing scandal and now Walker has been persuaded to withdraw after leaking Covid-19 patients' details to media.
Now the key question is: Has this affected the National Party's campaign for this year's election, which appears to have already started?
Some are calling the leak dirty politics. However, Walker says he was calling out the government's Covid-19 response and this document was proof of that.
Interim Health Minister Chris Hipkins has suggested this is an 'unacceptable' privacy breachand could be criminal.
National leader Todd Muller has accepted Walker's resignation and party officials will meet today to choose a replacement candidate for Clutha-Southland.