MP Judith Collins is the first candidate to put her name forward for the National Party leadership.
She tweeted today: "I'm announcing my candidacy for Leader of the NZ National Party."
"We're going to need strong & decisive leadership if we’re going to win in 2020. I'm that person."
The Papakura MP is considered one of the possible front-runners to replace leader Bill English, who on yesterday announced he would be leaving parliament in two weeks.
National MP Simon Bridges, meanwhile, has also hinted he may soon be announcing a run.
"At the moment I am talking to colleagues," Mr Bridges told media as he arrived at parliament on Wednesday morning.
"We'll just see what happens. It may be that I have more to say later today."
The member for Tauranga was not at Mr English's resignation - unable to make it to Wellington due to weather grounding flights.
Meanwhile veteran MP Nick Smith was staying tight-lipped about the race on Wednesday while Otaki MP Nathan Guy and Auckland Central's Nikki Kaye have ruled themselves out.
Mr English also wouldn't comment on his possible successors.
Half-a-dozen popular beaches across Auckland remain contaminated by sewage leaks, and unfit to swim, after heavy rain overloaded wastewater systems early this week.
The popular St Heliers Beach in Auckland's east is one of six with an active water quality alert on council's Safeswim online monitoring system.
Most of the prohibited beaches are along the south coast of Waitemata Harbour, directly east and west of Auckland's CBD.
On Monday this week, an unusually high 12 beaches in Auckland had water quality alerts on Safeswim's website including the very busy Mission Bay, and Mairangi Bay beaches.
However, these two popular Auckland beaches have now been cleared as safe to swim.
The description of the conditions on the Safeswim website is: "Real time sensors or manual inspections of the wastewater (sewage) network have detected wastewater overflows affecting swimming spots – swimming is not advised."
Contamination of Auckland's beaches does regularly occur following large storms when overflowing storm water seeps into the city's sewerage system.
Auckland Council typically discourages people from swimming in the city's beaches for 48 hours following a major storm event.
The six Auckland beaches with water quality alerts are:
- Herne Bay
- Home Bay
- Okahu Bay
- Point England
- St Heliers
- St Mary's Bay
To keep up to date with the water quality of Auckland beaches visit Auckland Council's Safeswim website.