We are voting House of Commons members and he is the leader of the party, not candidate for President
Actually he's got 30% votes and that means he will have 78 mandates of 200 total, because our system gives him bonus (we have proportional system with some majority bonuses for big parties and penalties for small one).. He needs at least one other party to support him at administration. Second place are democratic righties with about 11% of votes.
We will also have incredible 9 parties (it is record number since 1989) in House of Commons. So making any administration out of this will be very difficult.. We'll see. Maybe it will lead to some earlier elections soon.
Anyway as a custom the party with most votes gets first chance to form an administration and choose Prime minister.