A battle not worth winning

Since then things have changed dramatically. The former is still firmly within that tradition while the latter, like so many others, has moved on. They now have very different relationships with the church that nurtured them. One is known as Captain Catholic while the other is now vehemently criticising the church.

The tenor of these relationships, often centred on Cardinal George Pell of Sydney, offers insights into both Catholicism and contemporary Australian politics. Abbott's relationship with Pell has been a close one with the politician once describing Pell as his confessor. For Milne, on the other hand, both Pell's persona and his attitude to environmental issues represent what's wrong with the church she has left.

At a time when Abbott has played down his positive relationship with Pell, Milne, following the example of former leader Bob Brown, has ramped up her disagreements with him into a public statement of her disappointment with her former church. She accuses it of undue concentration on defending Catholic education while neglecting the big social justice issues of the day. The subsequent headline was ''Church puts cash before conscience''. In return Pell repeated his earlier claims that the Greens were ''anti-Christian'' and had a bitter hostility to Catholic teaching and church schools.

The dynamics of Catholic politics have a striking gender component to them. Across the world this has led to particular tensions between women and the church, including the current dispute between the Vatican and the Leadership Conference of Women Religious, representing female religious orders in the United States. These tensions are largely not about the church's refusal to allow even discussion of the ordination of Catholic women to the priesthood but rather the whole style and priorities of the church. The priorities of the conference include not just the environment but a deeply ecological approach to spirituality itself.

In Australian politics Abbott has been in the vanguard of the dramatic drift of Catholics into the Liberal Party. This is a phenomenon that he himself as spoken about and it is now a given. Abbott is the third Catholic federal Liberal leader in a row after Brendan Nelson and Malcolm Turnbull and the Liberal frontbench contains many others.

Women Liberal MPs have been part of this Catholic drift, including my sister-in-law Trish Worth, but they have generally not been as prominent. Partly this is because fewer women in general have reached the upper reaches of the parliamentary Liberal Party than in Labor and the Greens (to the dismay of reformers within the Liberal Party), but there is more to it than that. It is tempting to speculate that the twin impacts of the part played by questioning nuns in the socialisation of Catholic women and the gender dynamics inside the church have combined to produce this outcome.

This means that there are plenty of once-Catholic women federal MPs with views not unlike those of Milne, a fact that I confirmed when I conducted a series of confidential interviews with Catholic backbenchers and cross-benchers a few years ago. This research was published in Australian Quarterly magazine under the title ''Catholics in Federal Parliament''. Other former federal MPs with a similar background, such as Labor's Susan Ryan, have reflected in their memoirs on these questions of gender, church and social justice.

In Australian politics today there are no points to be gained either in so-called religious crusades or crusades against religion whatever your personal position. It is much more strategic just to leave the issue alone. While such crusades may be well received by your own close supporters, they don't win votes in middle Australia. They may even antagonise some mainstream voters.

Abbott has learned this. He has of course been deeply irritated when church leaders have criticised him and has often responded vigorously in kind. But now, while he makes no secret of his Catholicism it has been far less in evidence in his public remarks since he became leader. That course of action was helped by the demise of Kevin Rudd who was his sparring partner on things religious.

There has been far less sparring with Julia Gillard on this topic despite their differences. He is very co-operative with Catholic agencies and avoids conflict with them by and large. The controversial education question is handled by his Catholic offsider, Christopher Pyne.

The Greens haven't learned this lesson yet. The twin issues of education funding for Catholic schools and same-sex marriage threaten to wreck any relationship, though at the federal level at least some Catholic agencies maintain sympathetic working relationships. Undoubtedly the Greens feel under public attack from the church through some leaders and agencies.

Meeting fire with fire in such circumstances is certainly one option, adopted recently by the Treasurer, Wayne Swan, in his fiery dialogue with the mining magnates, Peter Forrest, Gina Rinehart and Clive Palmer.

Nevertheless often such public spats are fruitless or even counter-productive. The official Catholic positions on opposition to same-sex marriage and support for private schools are not going to change. Cardinal Pell remains their most prominent spokesperson.

Milne, like Brown before her, would be wiser to avoid personal clashes with him and instead concentrate on building and strengthening links on many other social justice issues with appropriate church leaders and agencies.

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

John.Warhurst@anu.edu.au