London, it seems, is worth a Mass. Such has been the influx of Catholic immigrants in recent years that a new study suggests that the old faith is on course to replace Anglicanism as the dominant religion in Britain.

Instantly reversing years of gentle decline, this is clearly the Roman Catholic Church in Britain’s “greatest opportunity”. It may also prove its “greatest threat”. No sooner has the late Cardinal Basil Hume been credited with fully integrating Englishness and Catholicism than a vast migration gives the faith a foreign accent.

We have been here before. Two centuries of suppression after the Reformation dealt Catholicism a punishing blow on the British mainland. When the restrictions on worship were relaxed in the 1770s and 1790s, the faith could be caricatured as the preserve of aristocrats and eccentrics. It was the mass migration of the Irish in the 19th century that rejuvenated the Catholic Church in Britain.

By 1841, 420,000 out of a British population of 18 million were Irish born. The potato famine rapidly swelled the number of Irish immigrants. By 1861, the figure had risen to 800,000 out of 23 million. What was more, these new arrivals — concentrated in London, Liverpool, the Lancashire cotton towns and Glasgow — often married other Irish immigrants. While the census figures showed a gradual diminution of the Irish-born proportion of the population after the 1870s, those growing up in culturally Irish, Mass-attending families continued to grow.

Shortly before his death in 1892, Cardinal Manning assured his successor that “eight-tenths of the Catholics in England are Irish. Two-tenths, say two hundred thousand, are English.” A few years previously, Manning had even admitted that he had “given up working for the people of England to work for the Irish occupation in England”.

There were many English Catholics who were less than overjoyed to be suddenly celebrating the sacraments with the dispossessed of Wexford. The huge Irish migration risked making English Catholicism, which had been self-satisfyingly exclusive, a bit déclassé. The new arrivals also made greater demands on the Church than it had the money to cover.

There was a potentially yet more serious problem, as Manning conceded. The influx frustrated his hopes that Catholics might play a greater role in the nation’s public life. In 1890, he pointed out: “A capacity for civil and public action needs, of course, a training and education, but it springs from a love of our country. The Irish have this intensely for Ireland, but can hardly have it as yet for England.”

The question for today’s Church is whether the Polish diaspora will learn to love their adopted home more quickly than did the Irish?

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