White Wagtail

Afraid it looks like a well marked Pied Wagtail to me rather than a White Wagtail.

In fairness, having just looked it up, the Pied Wagtail is a North European sub-species of the White Wagtail, so in that sense yes it is a White Wagtail :P

The info on here looks like it could very well be a White Wagtail.

Pied and White Wagtail Identification