Flello, who was previously the Labour MP for Stoke-on-Trent South until losing his seat in the 2017 election, switched to the Lib Dems after disagreeing with Labour leader Jeremy Corbyn.
Just days after Flello was selected on 9th November to stand in the same seat for the Lib Dems for this week's general election, he was stood down.
He was told by party officials that his views on abortion and same sex marriage, shared on social media, were "not those that would be expected of a liberal" and it was therefore "not appropriate" for him to represent them.
Flello told Premier he believes he was deselected because of his religious beliefs: "What is interesting is initially the Lib Dems, having told me that they were deselecting me for my views, and then over the course of the week that followed, they gave me all sorts of other reasons and suggested that I retweeted a very aggressive tweet. But, I have not done those things.
"So, I can only conclude I'm absolutely convinced they are discriminating against me on the grounds of my faith."
"I feel I have no choice really, but to take legal action against the Liberal Democrats. There is no doubt in my mind, that what I have experienced is discrimination on the grounds of me being a practicing Christian; having the views that I have, which are totally in tune and in keeping with being a practicing Roman Catholic."
Explaining what he hopes to achieve, Flello told Premier: "Showing the Lib Dems that they cannot behave in a way that is discriminatory and I feel I have to stand up for practicing Catholics in the UK, and more widely for Christians that would have mainstream Christian views on life and according to the sanctity of life.
"I also feel I have to defend democracy and stand up for it, because I think democracy is under threat, where you have a situation where people won't get a chance to vote for someone who is a practising Catholic, I think I had a very good chance of winning the seat, we will never know now.
"I was a Liberal Democrat candidate for about 36-hours and currently am no longer a candidate for anyone or anything. If necessary, we will go to court. I hope that the Lib Dems see that they have behaved in an appalling way and will take some action to try to remedy things."
Jo Swinson's party responded in a statement to Premier. A spokesperson: "We have members from a wide range of faith and belief backgrounds, and, being liberals, we believe that we should be tolerant and respectful of those who may not share our views. As with other political parties, we do not whip our MPs on key matters of conscience and will continue to do so.
"Unfortunately, in Mr Flello's case it was his activities on social media, tweeting or re-tweeting items that were well beyond the values of the party.
"We believe that our candidates should be held to a higher standard of behaviour than our members, reflect our values and policies, and not bring the party into disrepute. By directly associating himself with comments and causes Mr Flello put himself outside the standards we would expect for a Liberal Democrat candidate."
Flello said he had not decided who he is going to vote on Thursday and will be spending time "praying and thinking" about it, but said he has not ruled out spoiling his ballot paper.
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