National Party's chief of staff Wayne Eagleson, right, with John Key, centre, play a round of golf in December last year.

National leader Bill English's chief of staff Wayne Eagleson has resigned.

Eagleson has been a pivotal figure for the past nine years in the National government, and Stuff has been told he will stay on for the next few weeks while negotiations carry on to form a government.

Eagleson was particularly close to former leader John Key and stayed on after English asked him to do so following the change of leadership.

MAARTEN HOLL/STUFF Bill English's chief of staff Wayne Eagleson has quit.

But he had been widely expected to go after the election.

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Key once described Eagleson as New Zealand's "most influential unelected official".

Once private secretary to former Prime Minister Jim Bolger Eagleson was often said to be the one running the country when Key was out of town."When Eagleson says it, Key says it," many an insider has been known to say, and the MPs believed it too.

Eagleson was one of the earliest appointments English made, before he himself was formally appointed in fact - a testament to just how much his strategic mind is valued by the National Party.

He has been hugely influential behind the scenes in National and his attributes of being calm and unflappable were seen as contributing to the Key Government's success.

He was also an important conduit between National and its minor party allies so whoever replaces him will have a pivotal role in relations with potential coalition partner NZ First.

Regardless of what happens in coalition negotiations, Eagleson may not be the only high profile figure within National to quit. Elections are generally seen as watershed moments and after a decade in power many staffers will see it as a good time to utilise their contacts and networks within Government to establish themselves in new careers.

They won't be banking on National winning a fifth term and those contacts will lose currency as time goes on.

Of course if coalition negotiations fall over and National ends up back in Opposition there will also be a large number of job losses. It is a nervous wait for many of them while they wait to hear if they still have a job.

Some longer serving MPs may also decide during this term of Parliament to hang up their hats, particularly if National ends up back in Opposition.