Sea birds rescued after they were contaminated with a colourless synthetic rubber are to be released back into the wild.
More than 300 birds, mainly guillemots but some razorbills, were taken into care by the RSPCA after being contaminated with Polyisobutylene (PIB) or butyl rubber.
They were rescued along the south coast shores at the end of January.
Tomorrow the birds will be taken to a cliff-top in the Portland area of Dorset, where most of them were found, and then released.
Peter Venn, manager at West Hatch rescue centre, said: "Our staff have done a fantastic job in cleaning and caring for these birds and now some of them are strong and fit enough to be released back to the wild where they belong."
It could be days before the true scale of the pollution spill affecting sea birds on the south coast is known, wildlife experts said today.
A change in wind direction could have killed thousands more birds after scores were found washed ashore along England's south coast.
Increasing numbers of birds are washing up on the south coast after being covered in a mysterious substance.