Donations are an issue that will not go away – and that is particularly the case for the National Party.

There was nothing illegal or new about the $150,000 donation from Chinese billionaire Lang Lin to the National Party, made through his New Zealand registered company which runs his horse export business.

It was duly disclosed in 2017, and well covered by media at that time because of the size and the source - Lang, whose nickname is "Mr Wolf".

Focus: PM Jacinda Ardern, Todd McClay and Simon Bridges on $150,000 donation to National. Video / Jason Walls / Boris Jancic

What was new in this week's revelations was the detail of how the donation came to be made.