A holiday resort in Bedfordshire said it was "deeply offended" after unwittingly hiring out a meeting room to Britain First.
The award-winning Wyboston Lakes resort said the far-right group booked the £2,250 room under a different name for its conference.
Pictures posted online by Britain First leader Paul Golding showed dozens of people sitting in a room decorated with banners declaring, "Taking Our Country Back!" The resort was hit by an online backlash after the images surfaced.
The conference was booked under the name Patriot Merchandise, which had no clear connections to Britain First, a spokesperson for the resort said.
Patriot Merchandise is listed as a Belfast-based PLC.
The spokesperson added that the banners were erected only in the "closed off conference room” and the money the resort made from the five-hour booking on Saturday will be donated to charity."For the sake of clarity, had we known the nature of the event being held by Britain First, we would not have taken the booking, as the values of our organisation conflicts with theirs in totality," the spokesperson said.
"We can fully understand the concerns expressed, but we can only refer to our company values and principles, our standing as an award-winning employer and assure everyone that we are deeply offended by their presence on our property."
The conference came amid a diplomatic spat between the US and UK, after Donald Trump retweeted three anti-Muslim videos posted by the group's deputy leader Jayda Fransen.
Following the retweets, the group said it had received hundreds of new membership applications.