MEPs Catherine Trautmann of France, Hannes Swoboda of Austria and Stephen Hughes of Britain are intensifying their campaigns to lead the Socialists & Democrats, in what will be the first competitive election in the political group's history.
Speaking to EURACTIV, Mr Swoboda said: "This is the first time we have different candidates! In former times it was always that the party leaders just decided who it should be."
He noted that when Martin Schulz, the current leader, first took office in July 2004 he was elected by Socialist MEPs, "but there was only one candidate, Martin Schulz."
The MEPs have been active over the past week sending letters and directly lobbying heads of national delegations and other colleagues to support them in their bids for the leadership.
The Socialists & Democrats group is the second largest in Parliament, after the centre-right European People's Party.
The candidates appeared to be at pains to differentiate themselves and their programmes which emphasised similar planks in areas such as internal group democracy, inclusiveness and transparency in decision-making.
For example, while Trautmann's letter says she would welcome contributions from "every member, every delegation – small or big – every collaborator of the Group," Hughes's promises "to promote unity in the Group by calling upon the skills and talents of all members and staff."
When asked about the similarities between their programmes, Maxime Herrmann, parliamentary assistant to Trautmann, suggested Hughes "is following Catherine's lead. He repeats points at times because he came out with this letter the day after Catherine's."
Swoboda similarly stressed his unifying potential, contrasting Schulz's famously confrontational style with his own, he said "My strength comes from trying to bring all the members and their ideas into debate and so to find compromises."
Less voting by national bloc?
There appears to be little indication at this time as to who might triumph in January. A source close the S&D Group said of the contest "it's quite open. I would not risk making a prediction."
The leadership of Parliament political groups are often entrusted to candidates from the larger countries in the hope that they will hold sway over a greater number of members. For example, the leadership of the EPP, Socialists, and Greens are all currently held by French and Germans, all incidentally German-speaking.
However, it looks that the size of the Socialists' national delegations may play a relatively small role this time around. None of the frontrunners are from one of the Socialists' 'big three' delegations with over 20 MEPs (i.e.: German, Italian or Spanish).
Mr Herrmann argued the Socialists "are having a secret ballot so [the vote] won't necessarily be by delegation." He added that internal divisions, "particularly in the big delegations," were likely to prevent voting by national bloc.
This may augur well for Swoboda's candidacy as an Austrian MEP. "It's high time to have a shift towards … smaller and medium-sized countries," he said. "Europe is more than some big countries."