The Pope's long-awaited ruling on Catholic morality, to be published next week, takes an even harder line than expected against artificial birth control and rejects any weakening of traditional prohibitions against divorce, abortion, premarital sex and homosexuality.

A leaked version of the encyclical, Veritatis Splendor (the splendour of truth), says such acts are intrinsically evil. It goes on: 'A good intention or particular circumstance can diminish their evil but cannot remove it.

'They remain irremediably evil acts per se and in themselves they are not capable of being ordered to God and to the good of the person.'

The encyclical's uncompromising rejection of individual conscience and lack of concessions to modern lifestyles will anger many liberal Catholics, including senior bishops in the United States and Britain.

Speaking out against liberal priests and bishops who have allowed laxity on grounds of individual conscience, the encyclical says 'circumstances or intentions can never transform an act intrinsically evil . . . into an act 'subjectively good' or defensible as a choice.'

Largely the work of Cardinal Joseph Ratzinger , the hard-line traditionalist who heads the Office of the Doctrine of the Faith, the encyclical does not mention the doctrine of papal infallibility, the notion that the Pope cannot be wrong when making certain statements.

The 179-page document rejects interpretations of morality which Catholic theologians have elaborated since the liberalising Second Vatican Council in 1962.

'These trends of thought have led to a denial . . . of the fact that the natural moral law has God as its author, and that man, by the use of his reason, participates in the eternal law.'

It makes it clear that there is no room for argument and that the way to salvation is through obedience to the Church.

It complains that 'some currents of modern thought have gone so far as to exalt freedom to such an extent that it becomes an absolute, which would then be the source of values. This is the direction taken by doctrines which have lost the sense of the transcendent or which are explicitly atheist.'

Any idea that sexual behaviour can be adapted to individual choice is also rejected.