The "faith" of course is the Protestant one. Here is a link to an article on a very fuindy website, but AFAICS, the details that they have are accurate, and what is in the article is indeed the case.

The Protestant Succession to the Throne ACCORDING to the widely-publicised remarks of composer James MacMillan, and an essay by emeritus professor Patrick Reilly, prejudice against Roman Catholics pervades Scotland. But never has Roman Catholicism in Scotland or England had a higher profile or a better press than today. This is seen, for example, in the way that some newspapers support Rome in its desire to abolish the Protestant nature of the British Throne. The Coronation Oath makes clear that the Throne is Protestant: "I do solemnly, and in the presence of God profess, testify, and declare, that I am a faithful Protestant, and that I will, according to the true intent of the enactments which secure the Protestant succession to the Throne of my Realm, uphold and maintain the said enactments to the best of my power according to law." The enactments referred to are, of course, the Bill of Rights of 1689 and the Act of Settlement of 1701. The British Monarchy official website states, "The succession to the throne is regulated not only through descent, but also by statute; the Act of Settlement confirmed that it was for Parliament to determine the title to the throne. The Act laid down that only Protestant descendants of Princess Sophia . . . are eligible to succeed. Subsequent Acts have confirmed this. Parliament, under the Bill of Rights and the Act of Settlement, also laid down various conditions which the Sovereign must meet. A Roman Catholic is specifically excluded from succession to the throne; nor may the Sovereign marry a Roman Catholic. The Sovereign must, in addition, be in communion with the Church of England and must swear to preserve the established Church of England and the established Church of Scotland. The Sovereign must also promise to uphold the Protestant succession." Solemn and dignified as these statutes are, The Daily Mail of 10th August had the temerity to state that "there is a blot in the statute book which it is surprising to see tolerated in Tony Blair’s ‘inclusive’ Britain: the crudely anti-Catholic wording and provisions of the Act of Settlement. It discriminates purely against Roman Catholics; it is, literally, institutionalised sectarianism. The Act is long overdue for amendment". Such comments echo William Hague’s description of the Act of Settlement as "offensive", and Sir Michael Forsyth’s despicable comment in January, that the Act is the British constitution’s "grubby little secret". These calls for abolishing the Act are a call to all true Protestants to be prayerfully vigilant. Rome has at least indirect but significant influence in the political life of our nation. Not only would that influence increase if our constitution ceased to be Protestant, but also our dearly-bought Reformed, Protestant faith would be subverted. Three years ago The Times said that any attempt to repeal the Act of Settlement "would engender howls of protest from the deeply Protestant corners of the United Kingdom". May it be so! But especially may Almighty God mercifully preserve the Protestant nature of the British Throne.

from http://www.fpchurch.org.uk/magazines/fpm/1999/september/article8.php

Note the FP church is seriously fundy, but they have a fascinating amount of info on their website about stuff like this.the Coronation Oath, the Act of Settlement, and other historical things.

:-) SG