Kinda. Generally 70% would be paid by the loser, and it works more or less motion by motion.
So for example, in Wright v McCormack, McCormack was able to show at trial that Wright's claims of damages were intentionally falsified. This got McCormack a 'loss' where he only had to pay 1 pound and where he was awarded his fees for the trial (well probably 70%, that hasn't been decided yet)-- but in the interest of finality the trial court declined to reverse the 900k pounds in fees he had to pay for the other sides costs in earlier motions.
This also potentially provides an additional avenue to hit your opponents during a SLAPP-- sandbag your costs so that whatever the opposition does have to pay on motions they lose are ruinous, and also so they have to spend a lot defending themselves so that 30% they can't recover is also ruinous.
Full cost on trial like this-- with discovery and experts, etc-- may be on the order of 10 to 20 million pounds. Would you expect a volunteer open source developer to be able to pay a non-negligible part of that, on top of the substantial imposition on their life and time that fighting the case and winning entails?
