In the process this Catholic-cum-Anglican churchgoer built bridges effectively to Christian lobby groups such as the Australian Christian Lobby. Opinion varies as to whether it made much difference at the election, but it certainly didn't hurt.

At the 2010 election the dynamic was different, though formally Julia Gillard maintained those bridges. Nationally religion wasn't a big issue though Gillard had declared herself an atheist and allowed Labor MPs a conscience vote on gay marriage. She herself was just as socially conservative on policy questions as Rudd though not in her lifestyle. It was the Greens who took the heat from some church leaders including the ACL and Cardinal George Pell. Nevertheless, it appears that some denominations, including Catholics, were attracted away from Labor towards the Catholic Opposition Leader, Tony Abbott.

In 2013, Rudd is both the same and different as far as religion is concerned. His church practices are much in evidence again and he remains perhaps the most churchgoing of any of the 27 Australian Prime Ministers. He was very quick after his reappointment to call urgent meetings with Catholic and independent school leaders to discuss school funding reforms. But he has also changed his mind on one important policy question and now supports gay marriage.

This point of difference with Abbott has disappointed the ACL. But Rudd, ever the strategist, would certainly have thought through his public announcement on gay marriage and done his sums on the electoral impact.

So what do the churches think about the new Rudd? If past elections are any guide they will certainly let us know. Will Rudd try to rebuild relationships with the ACL, or will he forge a new path?

The churches are active at election time, none more so than the largest denomination, the Catholic Church. The Australian Catholic Bishops Conference (ACBC) has got in early and just issued its regular pre-election advice to Catholic voters, called this time ''Vote for the common good''. The document maps out major themes based on the principles of what is called Catholic social teaching. Right up front it makes it clear that such principles ''cross party boundaries and Catholics may, in good conscience, form different opinions on the candidates and parties standing for election''. It encourages Catholics to be active in the democratic process, to get involved by meeting local candidates, and even considering standing for office themselves.

More importantly, the ACBC encourages Catholics ''to look beyond their own individual needs to apply a different test at the ballot box - the test of what we call the common good.'' It lists 10 issues for consideration. There is no suggestion of priorities within these 10 by way of a ranking.

The 10 issues are: poor and vulnerable, marriage and family, child protection, life, indigenous Australians, refugees and migration, education, health, peace and development and ecology and sustainability.

Will the political parties even bat an eyelid? There is a respectable case to be made that, despite making up a nominal 25 per cent of the population, the reputation of this church is so battered and church attendance so feeble that no one should care at all.

There is also the practical problem of getting the word out to a wider audience beyond the 20 per cent (to be generous) of regular church attenders. A document like this is easily submerged in the mass media. Even Catholic loyalists may not worry what their leaders have to say.

But the party leaders, both well connected in church circles, will take notice, if for no other reason that any election win is made up of a half a per cent here and a half of a per cent there. Even the debilitated

churches form one of society's effective political blocs. This document itself may not matter, but if history is any guide some Catholic bishops will break loose from their collective statements during the campaign proper and effectively back one side or the other.

Cardinal Pell may be quieter than usual this time on major party politics.

My reason for saying this is that he may hinder rather than help Abbott if he chose to put his weight behind him even implicitly.

The Pell-Abbott relationship works among some churchgoing Catholics but not among the community at large because it awakens their fears of Catholic tribalism. It evokes the old rather than the new Tony. But back to ''Vote for the Common Good''. It should be read not just for what it says about major party competition (it doesn't play favourites) but for what it sees lacking on both sides. Catholics, along with other Christian churches, have been critical of the mainstream consensus on economic and social policy for decades.

Reading between the lines, it is notable that the poor and vulnerable are mentioned first. The cruel treatment of the unemployed offers both sides a chance to do something about raising Newstart benefits to a humane level.

Equally, the church is at odds with both sides on refugee and asylum seeker policies because it wants all strangers welcomed to our shores and given due process. Though the language is careful, voters who object to both Labor and Liberal toughening up treatment of asylum seekers have an ally in the Catholic Church.

John Warhurst is an emeritus professor of political science at the Australian National University.

John.Warhurst@anu.edu.au