Senior Labour TDs say Minister for Social Protection Joan Burton is stealing a march on her leadership rivals by attempting to secure the support of as many deputies as possible.

Ms Burton’s supporters said it would be important to get the support of TDs and Senators in the race to be leader, even though the electorate is made up of all members of the party.

However, it is widely acknowledged in Labour circles that Ms Burton’s main weakness is her lack of support in the parliamentary party, with Minister for Public Expenditure Brendan Howlin and Alex White, Minister of State at the Department of Health, seen as more popular among Oireachtas members.

Grassroots Ms Burton's main strength is seen as her popularity among the party grassroots.

Amid speculation in Leinster House that Mr Howlin will not contest the leadership, sources close to him stressed he had yet to decide whether he would stand. Most TDs and Senators are waiting until all declarations are in before deciding who to support.

Ms Burton, the party’s deputy leader, spent part of yesterday discussing her candidacy – which she will formally declare today – with TDs and Senators in Leinster House, as well as on the phone.

“She’s locking it up, she’s locking it up quite quickly,” one TD said, while adding the “latest Brendan could come on the pitch” was today.

However, a number of senior deputies said there must be a contest for leader, with the mandate coming from members, for the good of the party.

“Whoever is elected they must have a mandate,” party whip Emmet Stagg said. “It would be better for the party if the leader had a mandate from the party, and not just of the parliamentary party.”

Ciaran Lynch, the Cork South-Central TD and chairman of the Oireachtas finance committee, said the election of a new leader “must be one that involves the members and not some trade-off presented to them”.

“I will be deciding on who has the best direction, ideas and plan for the party rather than simply on personalities.”

Ms Burton and Minister of State at the Department of Transport Alan Kelly are the only candidates actively canvassing at this stage in the campaign. Numerous sources suggested Alex White had been damaged by the perception he was involved with the gang of eight who tabled a motion of no confidence in Eamon Gilmore.

Alan Kelly is considering whether to run for leader or deputy leader and said he would make a final decision in the next 24 hours when a clearer picture of the field of candidates emerges.

“There needs to be generational change at some level in the leadership,” the Tipperary TD said. “The decision I will have to make will be for what’s best for the party, not what’s best for Alan Kelly.”

A host of Labour TDs – including Kevin Humphreys, Ciara Conway, Ged Nash and Dominic Hannigan – are considering running for the position of deputy leader.

It is expected that about 5,000 members will be entitled to vote, with lapsed members getting the chance to pay overdue fees in the coming weeks to enable them to vote.

The largest membership clusters are said to be around Longford-Westmeath, where Willie Penrose is the TD; Mr Stagg’s Kildare North base; Dublin-South East, where Minister for Education Ruairí­ Quinn and Mr Humphreys are TDs; and Mr Howlin’s Wexford base.

Low membership Ms Burton's Dublin West constituency is understood to have low membership, with one source saying just 30 people turned up to a recent byelection selection convention.

However, sources in the party said the rank-and-file members would not follow the lead of their local TDs, stressing it was a “very independent electorate”.

“It would be a mistake to try and run on bloc voting,” one senior figure said. “The members are very tuned in.”

LEADERSHIP CONTENDERS By Fiach Kelly and Mary Minihan

JOAN BURTON The Dublin West TD is the early favourite, and was quick out of the traps on Monday, canvassing backbenchers for support almost immediately after Eamon Gilmore announced his resignation.

Ms Burton has worked the grassroots assiduously in the past three years. She is also the most popular Minister among members of the public.

She would not have much support in the parliamentary party, although Carlow-Kilkenny’s Ann Phelan and Dublin Mid-West TD Joanna Tuffy would be expected to back her. Her main strength is among the rank-and-file members.

Ms Burton has consistently said Labour should be the party of work, rather than a party of welfare. She will also emphasise the need for Labour to refocus on its strengths in the public sector and with the working class.

Her supporters will also point to her appeal to the average voter. TDs could be persuaded she will be the most acceptable face to have on posters come the election.

BRENDAN HOWLIN The Minister for Public Expenditure would command wide support in the parliamentary party, and many TDs have paid tribute to his ability to handle budget negotiations. It could boil down to a straight fight between him and Joan Burton.

While Labour parliamentary party members are keeping their cards close to their chests, there is a feeling that some of the influential older TDs, such as Willie Penrose and Emmet Stagg, could row in behind Mr Howlin, possibly bringing their strong membership bases in areas like Westmeath and Kildare with them.

The Wexford TD could pitch himself as a safe pair of hands to steer Labour in Government through the difficult budget expected towards the end of this year. Deputies and party members anxious to avoid an early general election could opt for Mr Howlin. He could draw on the strength of rural TDs who would like to see a leader come from outside the capital, following the leaderships of Ruairí­ Quinn, Pat Rabbitte and Eamon Gilmore. ALEX WHITE The 55-year-old barrister and former producer of The Gay Byrne Show has impressed a cohort of colleagues, who would like to see a media-savvy performer as party leader.

The Dublin South deputy is undoubtedly persuasive and highly intelligent, but doubts remain as to whether he could encourage enough ordinary members of the party to back him in a contest with longer-serving competitors.

Perceived as a liberal-leaning lawyer, some colleagues outside the capital suggest he might struggle to extend his appeal beyond a Dublin-centric, middle class niche.

His expertise as a legislator came to the fore during the fraught abortion debate. A first-time TD who had served a term as a senator, Mr White’s accomplishments were recognised when he was promoted to Minister of State for Primary Care in 2012 following Róisín Shortall’s departure.

ALAN KELLY The Minister of State at the Department of Transport would not be considered a front-runner but it would be unwise to completely rule him out of contention. His focus may be on securing the position of deputy leader and the expected full Cabinet post that would probably come with it.

If Joan Burton were to become leader, Alan Kelly could position himself as a male, young and rural counterbalance to her. He could gather support from a combination of those arguing for a generational change and those pushing for a rural presence at the top of the party. Kelly is based in Nenagh, Co Tipperary, but would not command wide backing in the parliamentary party. Expect Mr Kelly to emphasise his youth to play on those who want to see the rainbow coalition generation pass the baton, as well as a desire for renewal and regeneration of Labour.

His backers hope he would get support in the rural strongholds of Willie Penrose, Jack Wall and Emmet Stagg but he won’t be alone in hoping for support from those quarters.

ARTHUR SPRING The likelihood of the Kerry deputy, a nephew of former tánaiste Dick Spring, becoming leader is slim. If he contests, the former banker and juice bar owner would be hoping to appeal to a younger demographic among party members.

Some colleagues contend Mr Spring has not “earned his stripes” and contrast the first-time TD’s low profile with that of better known and more experienced potential contenders.

He has emphasised the challenges facing couples with young families in what he describes as his “jinxed” generation, who bought homes between 2004 and 2008 and now struggle with negative equity. Mr Spring is a social democrat and an admirer of the Nordic model of society, having spent time in Sweden in his 20s.

He believes the party’s communications strategy should be improved and more emphasis should be put on defining exactly what segments of society the Labour Party is trying to engage.