Rainboe:
I repeat- we are not talking circling approaches! ATC have switched you to another runway.
Waitaminutehere!
What is the official definition of a "swing over" or "swing across" in CAA/JAA jargon? There is no such official terminology in the US, and I have never heard it before.
In the US there are 4 possibilities for changing runways:
1) Change to the ILS for the new runway, if you are outside the FAF for the original one. In that case, missed approach would be for the new runway approach.
2) Circle to land on the new runway. In that case, the missed approach would be for the original approach.
3) Sidestep to the parallel runway. This is ONLY valid when the sidestep is published for the approach to the original runway. Missed approach is still for the original approach.
4) Visual approach to the parallel runway. Since you are now visual, missed approach will be per ATC (Tower) instructions.