It is likely to send already-poor relations with the Government into deep freeze.
The contrast between the Cardinal’s approach and that of the Archbishop of Dublin Diarmuid Martin would also suggest a difference of opinion within the church.
Last month, Dr Martin confirmed that the church would reiterate its teaching on abortion and marriage equality, regardless of the progress of legislation on these issues.
But, he said, “before, during or after the enactment of legislation, the church’s teaching is to teach something, rather than to oppose it.”
Such a measured approach has now given way to actively lobbying and co-ordinated opposition.
Nobody expected the Catholic Church to modify its teaching that abortion is sinful in all circumstances.
Neither, however, was it expected to engage in aggressive political lobbying of the kind more usually found in the United States – though that is its right. The reason for the cardinal’s pre-emptive strike may be found in a Vatican report that emphasised the need for strict orthodoxy and control.
The document, ostensibly about clerical sex abuse in Ireland, was critical of a widespread tendency among priests, religious and the laity to hold theological opinions at variance with the church’s teaching, particularly in relation to celibacy, women priests, divorce and contraception.
By highlighting the issue of abortion and actively campaigning on that, however, the calculation may be that other internal divisions can be contained. It may be an unrealistic expectation.
Opinion polls have found that many Catholics have become alienated from their church on sexual matters.
A large majority favours the provision of abortion where the life of a mother is in danger.
And more than half of GPs surveyed said that abortion should be available to women who choose it.
It is 20 years since the Supreme Court ruled in the X case that it was lawful for a woman to have an abortion where her life was at risk.
Even in those limited circumstances, however, successive governments declined to provide the legislation necessary to give effect to the judgment.
Minister for Health James Reilly told the Dáil earlier this year that action would be taken when an expert committee reported.
Within weeks, 15 members of the Fine Gael parliamentary party had threatened revolt if legislation was introduced and they demanded sight of the report before it went to Government.
Tánaiste and leader of the Labour Party Eamon Gilmore later described abortion as “a sensitive issue” within Government.
So it is.
But so is control of the primary education system.
The Supreme Court and the European Court of Justice have ruled on the rights of women.
Ministers and politicians can no longer prevaricate.
They have to decide which takes precedence: canon law or the law of the land.