According to a new study, the Roman Catholic Church in England has within a year found itself experiencing an unprecedented expansion due to the increase of Catholic immigrants.

Several Catholic parishes, mostly in London, have gone from being predominantly Irish-English and on the decline, to very busy and multi-ethnic.

A new report by the Von Hugel Institute at Cambridge forecasts that, if current migration trends continue, Catholic parishes will swell by hundreds of thousands over the next few years. This type of growth means Catholicism may become the dominant religion in Britain.

In 2005, there were 4.2 million Catholics in England and Wales, less than one-fifth of the 25 million baptized Anglicans and double the number of Muslims.

While Catholic parishes have responded positively to the influx, others have been overwhelmed, as these new immigrants go there for assistance with employment and social welfare. Most of the migrants settle in London, where some parishes are reportedly putting on Sunday masses from 8 a.m. to 8 p.m. to cope with the demand.

The Cambridge report, the results of which were run in “The Times of London,” calls on the Catholic hierarchy to act urgently to help the migrants and the clergy by providing more resources.

The Catholic dioceses of Brentwood, Southwark and Westminster commissioned the Von Hugel report last May to investigate the needs of migrants in London.

The report is based on a survey of 1,000 migrants from diocesan parishes, ethnic chaplaincies and the Polish vicariate. Researchers also ran focus groups and interviewed clergy.