Word is, someone paid a couple of people in Pakistan to record the video without the party leadership knowing about it.
"Therese Hirst" is former Veritas candidate, Therese Muchewicz. Presumably her name was a bit too foreign sounding for the English Democrats and the BNP rejects that they've recruited into the party. Hirst/Muchewicz got just 98 votes in this year's general election which is quite good for the English Democrats who regularly lose to the Monster Raving Loony Party.