A BENDIGO cafe manager has said he "never expected to see that level of discrimination in Bendigo" after an encounter with anti-same sex marriage campaigners in his workplace.

Brewhouse Coffee Roasters manager Tim Dalton, who is gay, was working the floor of the cafe on Thursday afternoon when a group of eight entered, including City of Greater Bendigo councillor Helen Leach.

He said marriage celebrant Alan Howard spoke with him and attempted to hand over a letter which was initially meant for The Good Loaf.

Mr Dalton said Mr Howard explained the reason for the letter, which caused him distress.

"I became quite upset about it because of the way he was talking, he kept going on and on about how it was going to be the end for the traditional family and those arguments," Mr Dalton said.

"I had to go upstairs later and then go home, I haven't seen that kind of discrimination since I was in high school.

"I thought those days were behind me."

The conversation between the two included why the anti-same sex marriage group had chosen to dine at the Brewhouse instead of The Good Loaf, which was one of the 21 businesses included in an advertising campaign supporting same sex marriage.

Mr Howard said claims the encounter was distressing were "rubbish" and he had simply tried to hand over the letter to be passed on to the Brewhouse owner.

"My reasoning was that when I go in any business, I seek to engage them for products or services. I don't expect them to take from me or force on me social or political ideas, like those 21 businesses have done," he said.

"The meeting was just to discuss the impact changing the marriage act would have."

Mr Dalton said the way the conversation progressed left him upset, and he was "offended" that the group chose to stay and openly discuss the issue.

The group of eight individuals who entered the cafe sat down and had discussions with piles of paper on the table, which Mr Dalton said had anti-same sex marriage arguments on them "in big red letters".

The Brewhouse was not one of the 21 businesses who publicly supported same sex marriage, but intends to display a poster in its window declaring its support.

Mr Howard said the group of individuals was entitled to their view and had a right to hold a discussion in the cafe.

He said he was cynical of the motives of the 21 small businesses who publicly supported same sex marriage.

"I feel, in the absence of any other knowledge of the 21 businesses, that it was a simplistic and opportunistic marketing ploy to run with the hounds on the issue of same sex marriage," Mr Howard said.

He said the group had no plans to distribute pamphlets to any groups or people.

Cr Helen Leach, who was present with the group, agreed with Mr Howard's point of view.

"It certainly looked like a marketing thing to me, that they are trying to make the most of the bandwagon," she said.

She denied the group was behind the anonymous letter sent to the 21 businesses condemning them for their involvement in the advertising campaign.