Transport Minister Simon Bridges has declared his bid for Deputy Prime Minister.
He has also endorsed Bill English for Prime Minister.
At a press conference this afternoon, Bridges said English would continue the stability of the John Key-led National Government.
He said that as Deputy Prime Minister, he would provide the "change and rejuvenation part of the equation".
Bridges said he was confident English would win the leadership race and he had not yet considered being part of another ticket.
The "whole premise" of his bid was an English-Bridges leadership, he said.
And although he has discussed the matter with English, he would not say whether English is supporting his bid.
Bridges, 40, has been in Parliament since 2008 when he defeated New Zealand First leader Winston Peters by more than 11,000 votes in the Tauranga seat.
Since being promoted to Cabinet in 2013, he has held the energy and resources, labour and transport porfolios.
The contest for Prime Minister remains a three-horse race between Deputy Prime Minister Bill English, Health Minister Jonathan Coleman and Corrections Minister Judith Collins.
Bridges could be competing against Social Housing Minister Paula Bennett for the deputy role. She has previously been tipped as a deputy under English, but has so far refused to say whether she will run for the leadership or deputy leadership.
Bridges said he marked a "clear generational change". He also said he was not part of National's "inner sanctum" or "kitchen Cabinet" - an apparent suggestion that he was more engaged with, and could have more support from National's back benches.