Unknown spider (fairly large)

Unknown spider (fairly large)

Observation - Unknown spider (fairly large) - UK and Ireland. Description: Fairly large (approx 5cm) spider spotted while taking part in the 2012 Garden bioblitz. It was quite large and found under a plant pot. Any help with ID most welcome.

Fairly large (approx 5cm) spider spotted while taking part in the 2012 Garden bioblitz. It was quite large and found under a plant pot. Any help with ID most welcome.