don't think so.
Its almso tthe same as being at idel/netural (ie no load on the engine).
I would clean the throtlle body and butterfly of black diposts first with a can of carb cleaner.
Then clean the breather pipe thay goes from the rocker cover to the neckof the throttle body, clean that pipe out of the gunk that has collected up (again with carb cleaner). If too much gunk gets chucked out, it will begin to clog the ISCV and idel will be difficult. Also check all air intake pipes and routes are doen up tight, no air leaks, cuts or splits etc. When was the last time you changed the air filter?
It's a panel filter and it's been working fine for the past year. I had it into a garage today and they said the mixture was very weak and they corrected it. The first junction I pulled up to, it stalled and took 2 or 3 attempts to start it again - they're going to look into it again tomorrow.
Does £260 sound reasonable for a clutch to be supplied and fitted?