Labour's New Lynn electorate committee is considering making a complaint to the party's ruling body over the treatment of their MP, David Cunliffe.
Mr Cunliffe was demoted on Tuesday after failing to quell speculation he would challenge for the leadership.
Greg Presland, a spokesperson for the the New Lynn Local Electorate Committee, told Morning Report he is deeply concerned there is an element in the party trying to sabotage Mr Cunliffe's reputation.
He said Mr Cunliffe, like other MPs, should not have been forced to reveal the way he was going to vote in future ballots.
However, former Labour minister John Tamihere, who is considering a comeback to politics, said Mr Presland should pull his head in.
John Tamihere told Morning Report that politics is a hard game and the New Lynn electorate committee has to accept that Mr Cunliffe lost.
Labour leader David Shearer said the Local Electorate Committee has the right to make a complaint and that will be dealt with by the party's ruling council.