The Salt Lake Tribune is running an article about the criminal charges filed against Thomas S Monson by a UK magistrate judge:
It's not illegal for a church to preach whatever it wants, and it's not illegal for a church to accept money from it's followers. However, the UK's Fraud Act (http://en.wikipedia.org/wiki/Fraud_Act_2006) criminalizes coercing money from people on the basis of false representation.
This is not a religious matter. Neither the LDS nor any other church need to fear lawsuits for preaching that Jesus is the Christ nor any other religious belief. These charges have to do with members allegedly being coerced into paying tithing on the basis of six factual historical claims (not beliefs) that can potentially be disproven in a court of law. (These six claims are listed in the sidebar of the SLTrib article.)
I know this is a potentially contentious topic, so I don't expect a response to this. But I look forward to getting answers to some of the questions I have, either way.