Back in December Facebook was on the receiving end of some flack over the Britain First Facebook pages, particularly after Twitter suspended a number of accounts associated with the far-right hate group. At the time Facebook said it was "reviewing" the page, noting that the company was “very cautious about political speech”. Now, though, it's made the decision to ban the group's page, and prevent them from starting a new one.
In a blog post announcing the decision, Facebook emphasised that it was a big supporter of people having different views - saying that it can't just remove pages because a person or group of people don't like them. But Facebook isn't a big fan of spreading hatred against other sectors of society, crossing the line from legitimate political speech. That's why Britain First has been banned.
There will no doubt be plenty of people who support Britain First that will scream about how this infringes on their freedom of speech/expression rights. Because they don't understand that Facebook is a private company capable of setting its own rules about what is and isn't acceptable. It's already outlined what constitutes hate speech in great detail, and its community standards specifically prohibit it.
Facebook decided that content posted to its page by Britain First leaders Paul Golding and Jayda Fransen has repeatedly broken those rules, and when that content continued to be posted after a final warning the social network took action. The Britain First page and the pages for both Golding and Fransen have now been removed for "repeatedly [posting] content designed to incite animosity and hatred against minority groups."
There are still Britain First pages up on Facebook at the time of writing, though they appear to be parodies designed to mock the group in any way they can. The official, serious one is now gone, and it won't be coming back.