UK Hypothetical - Four-Way effective Tie

[Filinovich]

Imagine a scenario where the next general election is called and all of the four major parties received about a quarter of the seats in the Commons (either directly or among aligned smaller parties, such as the Greens with the Liberal Democrats). Three parties are needed to form a government. Which government do you think is most likely to be formed (if one is)?

In case you were curious, I've ordered the parties by their performance at the previous general election.