Could be a sensor catching? They only cost a few pounds from the dealer.
Had a similar thing happen on my old 200, it would some how 'catch' whilst taking a right.
If you take off the wheels you should be able to see whether the pads are worn or if you have a loose sensor. You could even take it to get a free brake test which those Kwik-fit style centres always offer (you don't have to agree to them doing anything!). I would however only use genuine pads, Textar or ATE. You can get them for around £30 a set from www.eurocarparts.com, there might be a branch near you.