Rubbery squeaks from rear suspension

[Tyre Smoke]

Wife's NB Icon squeaks over bumps when cold. At first I thought it was the spare wheel moving, it's that sort of rubbery squeak. After about five or six miles it becomes less obvious.

I'm guessing it's a bush or something. Any suggestions? Car has recently passed an MOT (May, but less than 200 miles since) so has something become a bit dry from standing idle?