In 1935 Italy invaded Abyssinia and UK seriously considdered declaring war to Italy, but found herself very unprepared for war.
Although the Royal Navy was much bigger than the Italian Navy, it for instance didn't have 15" shells in stock apart from those onboard the battleships, the Italian air force was considdered the strongest in the world, whereas the RAF was just a skeleton force, and the British Army was mainly a colonial police force. The shock of being so unprepared led to the British rearmament programme starting in earnest in 1936.
But what if - UK and Italy never the less do get into war? We could say added by some accidents of ships firing on each other, spin over Italian attrocities etc.
Regards
Steffen Redbeard