This would allow Corbyn or whoever leads Labour to have a shot at the majority and the position of prime minister. The Right-wing within Labour tried to oust Corbyn but he's being intransigent and refuses to back down.
Now it would appear Theresa May is slated to become the new Tory leader and hence the new PM. At that point there could still be a no-confidence vote but I think if Corbyn attempts it, he'll get egg on his face as many in his party don't back him.
So in the end, it may be that the Conservatives retain power and May will finish out the term until the 2020 election. But that's a long way off and if the Brexit negotiations and results don't go well then there's a good chance for an early election.
Theresa May's insurance is Jeremy Corbyn. As long as he's heading Labour, she's probably safe and secure at #10.