You don't give alot away, except I am guessing you are talking about Bournemouth. If so i am only guessing and a BOH ATCO will probably correct me.
Do you have to back track? Its possible that Bournemouth require a release from Southampton. Although BOH may have your clearance, it maybe that they expect it to be amended (maybe due local traffic). Therefore in order to have you ready, and to expedite the release from Southampton they line you up and only pass you the amended clearance in the first instance to avoid confusion and to save time.
I remember hearing at Coventry that Airways traffic had to be lined up ready to go before requesting release from Birmingham (again I could be wrong).
As I said, I don't know Bournemouth's operation (if it is Bournemouth) so I wait to be corrected.
