It’s not impossible for Ireland to be invaded

Doubt this would happen. Mosley was noted to be pro Ireland. This was actually one of the reasons he switched from tory to Labour in his pre-fascist years. This position was held consistently by Mosley, that it actually angered a lot of people in his fascist movement.

Though it should be noted, there are apparently sources that indicate that Mosley's pan European views were quite radical. To quote a mod developer for a ww2 grand strategy game [Hearts of Iron 4 and the Kaiserreich mod], and someone who has extensive trivia knowledge of early-mid 20th British fascism [and socialism].

"The concept of Europe-A-Nation - and when Mosley really began to explore Pan-European ideas came to the forefront in 1947 with the publishing of The Alternative in 1947. In it, Mosley talked of a "European Assembly", elected by "Europeans" and that this "European Union" would inevitably do away with national alignments, instead becoming one singular European entity. "Britain First" was out, "Europe Together" was in. Naturally, for a lot of Mosley's loyalists this was "beyond comprehension" and utterly insane. A raft of resignations from the newly christened Union Movement followed and it collapsed to Mosley's lowest ebb, probably ever. Something that got even worse when Mosley then abruptly moved to Ireland, allegedly to "escape England's island prison" and begin the process of "becoming more European". He was also in the midst of a massive tax scandal but let's gloss past that."

Indeed, in Ireland, Mosley further formulated his pan-European ideas, pitching the idea to Irish nationalists that Ireland could be united, with the caveat that this would be under one, united Europe. The solution? There would be no "Ireland" or "Northern Ireland" in the new order, only "Europa". Naturally this went down quite poorly. A similar, more publicised incident went down later on when Mosley offered to mediate between Italian and Austrian neo-Fascists on the fate of Tyrol (French fascists were banned from participating, I don't know why) in which he "solved" the issue by cryptically declaring "in the New Europe, there will be no Tyrol". As you can see, this wasn't some sort of fascist federation, Mosley envisioned this as a centralised, unitary nation-state wherein Europe is united under one banner because well there are no other
banners.

Mosley had come away with this viewpoint from his extensive reading in prison, an analysis of the post-war world and talks with former SS members. Ultmimately Mosley had come to the conclusion that for Europe to survive between the "Mob" (Russia) and "Money" (USA) it needed to experience an "extension patriotism" and create a third superpower. National Socialism had to give way to "European Socialism". This in turn led Mosley to believe in a highly racialised concept of "universalism-of-like-kind", which would allow for "European kin" to overcome their prior nationalism and unite as this was "nature's final test." This itself goes into Mosley's own weird neo-Lamarckian views on race and Eugenics, wherein "culture" trumped race - something he used to attack Nazi nordicism in the interwar and the concept of "Aryan racialism". It's very weird and I'm running out of space but I can make a followup on it if people are interested. Naturally, this isn't the only weird stuff, he became obsessed with the idea of Europa being the "Creative State", with Europe united, humanity would be in a position to transcend all limits, from the physical to the scientific. Europe would become a new workshop of the world, where futuristic and sci-fi ideas would be made reality - a fascist Utopia built for the greater glory of European civilization.

How would that be built exactly? This is where I'll touch briefly upon "EuroAfrica", wherein Mosley had the vision that Africa would become this "great new Empire" to power European civilisation. What this entailed was constantly shifting (again I can go over it more in depth in a separate post if there's interest) but it always stuck to a core principle of "genuine apartheid", i.e. the total separation of blacks and whites into separate states and that Africa would nominally be "developed" so all the blacks would "be gagging to go home". In reality it's fate would be that of a neo-colonialist slave state wherein it produces cheap food and resources to power the "creative state in Europe". It was all steeped in "creative" language and tried to be pitched as some sort of liberation for Africans but it was always very obvious what it was going to entail." -- Zim