This is probably a young juvenile who was told get lost by the parents due to the upcoming mating/nesting season. The young swan may be looking for a new territory and your feeding it is more than likely going to keep the bird in the area. He/she should be breeding next season, so at that time, he/she may return from the migration and may bring a mate with him/her.

Since swans are a wild protected species in the UK, we're not sure you could find it a mate. Being wild, the bird should do well on its own in finding a mate. The Regal Swan