More than half of all Fiji Labour Party members of parliament have backed their acting leader, Poseci Bune, against Mahendra Chaudhry.
17 of the 31 Labour MP's have put their support for Mr Bune in writing and sent it to President Iloilo, the secretary general to parliament and to the opposition leader, Mick Beddoes.
Earlier documents sent to Mr Beddoes by the party president, Jokapeci Koroi, attempted to show that Mr Chaudhry was the party leader.
But the dissenting group, which is now in the majority, have backed Mr Bune's claim that there was no Labour caucus meeting after the May general election to endorse Mr Chaudhry as leader.
Mr Beddoes says he sought legal advice on the letter written by the 17 MPs and sent both sets of documents to President Iloilo.
At issue is the appointment of eight Labour Party senators to the Upper House with both Mr Chaudhry and the dissenting group sending rival lists of nominees.
President Iloilo cannot decide which list of senators he should appoint until he is satisfied about who is the legitimately elected leader of the party.