Anything especially to check for before MOT ?

[Poodle]

As r3k1355 says, strip the caliper down and give it a good clean and regrease. Usual cause of binding with the rears is muck or corrosion on your sliders - a good clean and regrease should do it, but if they look that bad get new/refurbished ones. Bigg Red sell both, i've got a set of their refurbed jobbies in my rears that have done 15k and are still silky smooth.