In reply to Duncan Beard:
It's been a while since it's happened, but I think others have said it already - being first on a route is a choice. If you've got out of bed early enough then others should appreciate that and pick another route.
When they do catch up, it really depends on the circumstance. If it's a long wandery route and there's loads of time left in the day, then I'd consider it. If it's less than 4 pitches I'd probably not bother. A straight up ice route, or alpine big face, I'd be doing my best to speed up! Basically, don't let others "veneer" of confidence put you under pressure. Being second they don;t have to find the route, find belays etc. They're often gong to be quicker, but not necessarily quicker when out in front. Also you, by definition, have to wait a good hour or so for the leader and second to clear off ahead.
It once happened to me in Cogne, ice climbing. We were a group of 3 and got there just before a guide (off duty) with his wife and a friend.
We belayed in the obvious spot after P1. It was hard for us, so we weren't super quick. Mr Guide does a long pitch and asks if I mind him passing. I say "yes actually, this is an ice route and we arrived with a clear route, I try not to follow people on ice routes due to falling ice, so please don't overtake". I don't think he was expecting that! He said "oh, ok, I'll belay up and left".
Up and left was clearly pissing wet, so I thought, "oh well, he's going to get wet" Which he did...then decided being wet wasn't a nice option so overtook us anyway. Classic clusterfvck ensued.
https://goo.gl/photos/wYpniR2Cq2PvfEWr6
Luckily the wife & friend were cheery and chatty which made up for it a wee bit...