The idea
Various laws old and new are designed to make being a Catholic a crininal offence. A catholic cannot be the monarch of this country. The Catholic Church is discriminated against in equality laws that make some people or groups more equal then others.
Why is it important?
This country was a catholic country, It's laws, hospitals, university education, and numerous other things have their roots in the catholic church. You cannot write the history of England without the catholic church being mentioned (although government..etc do try to do this).
Catholics are citizens too and pay their taxes just like most other people (royalty and rich people who know the right loopholes excluded).
A Catholic cannot be King/Queen of this country by law – Where is the equality in that? Until the monarchy is disolved for good, a catholic should be allowed in this role if they have that desire and marry the right privilged person.
The catholic church ran the most successful adoption/fostering agencies for children, especially for hard to place (problem) children. The politically correct labour government admitted this but decided to pass an 'equality' law that shut the homes down or forced them to lose their catholic identity because they would not put children in families that were impossible to nature, even though statistics show that a child brought up with a mother and father in a stable family will do better than others from broken or irregular familes. Labour did not want facts but wanted to try a social experiment in the latest political fashion.
Catholics should be free to practise their faith and curently they are losing more freedom all the time from an anti-catholic society that has an anti-catholic establishment. Certain religions are given more freedom as the catholic church is sidelined ready for a coming persecution. This is how totalitarian or facist regimes divide and conquer. If catholics could declare a 'holy war' against the government, then they wouldn't be being picked on and bullied as they are. However, this is not the way to change things.
Give catholics the freedom that others enjoy. That will be true equality and diversity and also common sense.