One of the minor but curious questions about the PN leadership race is how it has come to be characterised by some pundits as a competition between the liberal and the Christian Democrat wings of the party. It is not.

The party support the three individual candidates are getting is not splitting up along ideological lines. (Indeed, political parties in Europe tend to divide along such lines in leadership contests only when they are going mad.) And none of the three candidates is a "liberal".

This might surprise readers who have become used to reading explicit or coded references to John Dalli as the liberal in the race. But when two days ago I asked Mr Dalli whether he was an economic or a social liberal he flatly denied being either. And I have yet to meet someone who has heard Mr Dalli champion social liberalism on the party's executive council or in closed brainstorming discussions concerning PN principles. (Some people have got the impression he is a social conservative but his manifesto contradicts this too.)

The flip side of the misapprehension of the role of liberalism in this contest is the misapprehension of the role of "solidarity" as a value. So far it has passed as the solution that the candidates are giving to the challenges before party and government. But solidarity is really a shorthand way of stating these challenges.

Back in the 1970s, "solidarity" was a broad fuzzy concept that served to establish Eddie Fenech Adami's credentials as someone who could be trusted to provide a safety net for those people who might not, on their own, be able to keep up with the sweeping changes he had in mind for Maltese society - particularly economic liberalisation, the EU project and the diversification of the labour market.

Solidarity was invoked to address an industrial society whose central concerns were how to provide an open but social market and how to minimise social and cultural exclusion based on class and status. The challenge for the new PN leader will be to make "solidarity" serve the same general function at a time when the major challenge is provided by the effects of demographic change, social liberalisation and cultural diversification.

The old concerns remain. But now solidarity needs to be shown in a society where the central axioms of the industrial dispensation no longer hold.

Job security, including white-collar job security, is a thing of the past; so is life-long employment with the same institution.

The existence of two separate labour markets, public sector and private sector, with two different sets of economic rules, is untenable. Economic marginalisation increasingly overlaps with lack of access to knowledge. Fewer households can make do with a single breadwinner. More households are being built by unmarried heterosexual couples, by homosexual couples and by single people.

In this world of risk, networks and identity politics, solidarity will have to mean concrete policies that show the contemporary relevance of the characteristic Christian Democratic concern - that the fundamental political units in society include not just the individual and the state but also families, voluntary organisations and other corporate groups in civil society.

Solidarity will have to mean, for example, a policy that legally recognises the plurality of forms of households, because it recognises the social significance of the duties and obligations that people sharing a household have towards each other. It must mean, to give another example, policies that support people who want to give up work to resume further studies (the current social policy does not). Stated this way, one can see three reasons why solidarity is a challenge to the PN as a governing party.

First, it requires a party leadership that can "read" Maltese society, see what is emerging from it, respond supportively and give what is creative in it an institutional voice. This is what the social policy ministry under Louis Galea did in many areas - for example, when it recognised that Malta was becoming an aging society before aged individuals themselves had a sense of collective identity. The ministry both responded to need - by providing, say, telecare - and tried to coax out the creative potential of the "third age".

Second, when the PN came round to implementing a systemic policy of solidarity that addressed the challenges of an industrialised society, it was fortunate that it had many European Christian Democrat models to follow. But the challenges that lie ahead - solidarity in an age of welfare reform and economic restructuring - still have to be resolved by other Christian Democrat parties. The PN has no authoritative model to follow.

So the new leader cannot speak, as Dr Fenech Adami did, of wanting Malta to join the normal world. Today normality is still under construction.

Finally, important swathes of the core vote of the PN can more easily absorb issues to do with solidarity with workers than with some of the new issues; those to do with different forms of household, for example. The new PN leader needs to persuade the party as well as the country of his understanding of solidarity.

He will need to use his roots in the party to make it grow new leaves. If he has no moral authority he will be lost.