BOOK REVIEW / The zealous march of a Catholic protester: Undiscovered ends - Bruce Kent: HarperCollins, pounds 15.99

THERE IS always something fascinating and destabilising about Establishment figures who turn on the system that has nurtured them. Much of the outrage about Anglican bishops criticising the Government, for example, springs from the fact that as the leaders of the Established Church they are assumed to be unswervingly on the side of the ruling classes.

Bruce Kent's background couldn't have been more Establishment. Conventionally and comfortably upper middle class, he was on the fast track to an anonymous career in the City or government service after officer training with the Royal Armoured Corps and reading law at Oxford. Only in his Catholicism, inherited from his mother, did he depart from the Home Counties norm. Even then his Protestant father made the best of a bad job by sending his son to Stonyhurst, the Jesuit equivalent of Eton.

However, the smooth transition from college scarf to pin-striped suit was rudely interrupted in Easter of 1949 by the oratory of Father Joseph Christie, who awakened in Bruce Kent thoughts of the priesthood. Even then, after his ordination in 1958, he seemed on course to climb the alternative ladder of ecclesiastical preferment, becoming, in the mid-Sixties, a youthful assistant to the then leader of English Catholicism, Cardinal Heenan. It was only during a spell as chaplain to London University that the campaign against the H-bomb hit Bruce Kent's G-spot.

In his eight years at the student chaplaincy, the man whose only brush with authority had been over a three-on-a-bike jaunt in Oxford cast off a lifetime's programming and took on the Establishment. Casual links with various reformist Catholic organisations gave way to a high-profile stance against nuclear deterrence.

In 1979, he took over as general secretary of the distinctly unrespectable Campaign for Nuclear Disarmament. If Bruce Kent was increasingly concerned about nuclear proliferation, the rest of the country had, at the dawn of Thatcherism, grown to regard it as yesterday's issue, From its peak in the late Fifties, CND had dwindled to 3,000 loyal members, a tiny budget and a two-room office.

Yet within a year of taking the reins, Bruce Kent was presiding at a rally of 80,000 anti-nuclear protesters in Trafalgar Square. For a decade his face was rarely off our screens. MI5 tapped his phone. Ministers and papal ambassadors accused him of being a Communist subversive. Someone sent him a parcel bomb.

The timing of his move to CND was divinely inspired. It coincided with news of plans to base US Cruise missiles in Britain and to replace the Polaris deterrent with the new, infinitely more potent Trident system. The Trafalgar Square gathering was just the first shot in a mass campaign of marches, protests and peace camps. CND membership shot up to 100,000.

But by the onset of the 1987 campaign the strain on Bruce Kent had become unbearable. 'I had had enough of being prodded and dissected by every journalist and politician with half an hour to spare,' he writes of his decision to leave the priesthood in 1987. His continuing pain and disillusionment are not disguised in Undiscovered Ends. He dismisses the distinction between unilateralism and multilateralism as a creation of the media.

The issue is more simple, he says. Are you for the bomb or against it? The Catholic Church pins its colours to the fence. Bruce Kent could no longer bear such equivocation. Just a year after he resigned as a priest, he married a fellow peace worker. News of their register office wedding was greeted with knowing smiles by his former colleagues, but he insists that his resignation was not a case of cherchez la femme.

Undiscovered Ends, its author concludes emphatically, is not a political obituary, although it candidly analyses CND's failure to win the debate. For those tempted to see Bruce Kent as just another face whose time has come and gone, he sets out a campaigning stance for the Nineties. But if there is one thing the Establishment dislikes more than a turncoat, it is a prophet. For all the talk of a new world order, this witty and passionate book shows that Bruce Kent still has a sure touch for disturbing the status quo.