Im getting a clunk from the rear passenger side in my 1.9 octy estate under braking, I have replaced rear shocks and bump stops with no improvement. The clunk doesn't happen consistently but very regular. Any ideas?

rear anti roll bar drop links?

Are they expensive to replace?

No i think i paid around £25 for a pair for the parts a year ago. Shd not take more than 15minutes per side as they are held by a couple nuts and only tools needed are a spanner and spline bit.