Labour MP Trevor Mallard says he willingly went out of leader David Shearer's Shadow Cabinet because he wants to be Speaker if Labour goes into Government after 2014.

In Labour leader David Shearer's reshuffle today Mr Mallard moved from 11th in the rankings to the unranked part of caucus outside the top 20. Mr Shearer only gives rankings to his Shadow Cabinet.

Mr Mallard said that was partly because he had put his hand up to be a Speaker in a future Labour Government.

"I'm hoping for a change of Government next year - the Speaker is not part of Cabinet and I think it's useful to get some fresh blood in there."

Labour put Mr Mallard up as a contender for the Speaker's role when David Carter was elected into the post to replace Lockwood Smith.

Labour's move was intended to be an objection to the Government's failure to consult them over who should have the role. However, it seems the idea that the stunt seeded has now taken root.

Mr Mallard said his rivals need not expect him to ease up on the political attacks in the meantime.

"I think I will have a role holding ministers to account through the internal affairs portfolio and I will continue my work as an advisor to the Speaker in the House."

As Shadow Leader of the House, Mr Mallard frequently takes points of order to object to Speakers' rulings and matters such as the way in which Ministers answer questions put to them.

When he announced the changes, Mr Shearer said that Mr Mallard and Lianne Dalziel - who was also demoted from the top 20 - had contributed a lot to the party and would continue to do so, but had both recognised the need for rejuvenation.