Mr Smith said: "They were shouting something about Brighton and accused us of attacking women and children."
A group knocked over the men's table before coming back a short while later in a group of around 10 men and one woman.
One man approached Mr Smith and began talking to him.
Mr Smith said: "In the middle of the conversation I had an uneasy feeling and he head butted me - one blow to the face.
"I was on the ground and sort of remember crouching, like a boxer who's gone down in the ring. I was completely dazed."
Now, I'm personally not much a fan of the SWP, but I'm even less of a fan of people being left looking this.
As it happens, EDL activist @Suzycasuals seemed to know something about it.
Very kind of Suzy to provide that information, especially given that her Tweeter feed is read by lots of anti-fascists. Because this subsequently happened.
Good work, Suzy!