On Thursday (19 March) I will be supporting a protest outside Dolce and Gabbana's flagship London store on Old Bond Street. The protest, which starts at 1pm, is a direct response to the designers' comments about same-sex parents and IVF fertility treatment, comments which I, like many others, found grossly offensive.

It is hypocritical for Stefano Gabbana, an openly gay man, to oppose same-sex parents, given that in 2006 he expressed a desire to have a child via artificial insemination and surrogacy. He's guilty of double standards. Gabbana wanted for himself what he now condemns other gay men for wanting. This is nothing short of a gross betrayal of the gay community.

I can't believe these two men are so stupid as to make such outrageous statements that they must have known would provoke a backlash. Cynically, I wonder if, having cornered gay consumers for many years, they're now keen to win over hard-line Catholic and right-wing consumers as well.

Instead of expressing regret, Dolce and Gabbana have gone on the offensive and lashed out at critics like Sir Elton John. I'm all in favour of showing mercy and forgiveness but I can't see how this is possible given their intransigent homophobia.

People have said we should ignore the comments and write them off as the intolerant, ignorant ramblings of two vacuous men in an equally vacuous industry. But I would disagree. Their words have given a propaganda gift to the opponents of LGBT equality.

Professor Susan Golombok, of the Centre for Family Research at Cambridge University, is the world expert on same-sex families. She's been studying them since 1976. Her latest research is in her new book, Modern Families, published last week. Surveying studies worldwide spanning four decades, she found that children with same-sex parents flourish, despite the stigma they sometimes face. So Dolce and Gabbana are ill-informed about the facts.

Moreover, Dolce and Gabbana are self-confessed Catholic loyalists. They are colluding with the Vatican's homophobia. The current Pope has introduced a more liberal, tolerant style, but the substance of Vatican policy remains implacably hard-line.

Senior members of the church continue to oppose LGBT equality and have disciplined priests who have spoken out for gay human rights. The homophobic catechism remains a standard document in every Catholic church in the world. Dolce and Gabbana have played into the Vatican's anachronistic, hugely damaging anti-gay attitude.

Local activists have also told me that Dolce and Gabbana's statement has been seized upon by the Italian far-right and used to justify their homophobia. The bigots are now saying that even gay people are opposed to same-sex marriage and same-sex parents. Given the menace some of these far-right groups pose, this is hugely dangerous.

And the potential for harm isn't limited to Italy. I spoke to Kato Asadhu Kayongo, a Ugandan gay man, who said: "Dolce and Gabbana's comments are so damaging to our struggle for equality in Uganda and other countries that criminalise same-sex relationships. Many people adore the Dolce and Gabbana brand in these countries. Such intolerant statements undermine our struggle.

"They are likely to be used by anti-gay activists in Uganda and elsewhere to reinforce their homophobic stance. It is very unfortunate that designers living in a country that mostly accepts gay people don't seem to care about the consequences of their outbursts to us who are still struggling against deep-seated prejudice and hate."

gay parents
Children from same-sex couples are actually healthier and happier than average. Getty Images

Thursday's protest is being co-organised by Edwin Sesange, director of the LGBT Out and Proud Diamond Group, who has said "we must send a clear message to Dolce and Gabbana that same-sex families are loving, happy families.

"This issue is not about same-sex families alone but also about the many straight families who have benefited from fertility treatment. Dolce and Gabbana's statements add to the stigma, shame, prejudice, rejection and intolerance often suffered by same-sex parents and their children."

I completely agree with these statements. Just take a look around. We can see so many happy gay and straight families who have benefited from donor insemination and surrogacy. It's brought these parents huge joy and resulted in children who have experienced great love.

Children born through IVF are just the same as every other child, apart from the method by which they were conceived. Who are Dolce and Gabbana to dismiss these kids as chemical and synthetic?

Ultimately, whatever Dolce and Gabbana's plan was, it's almost certain to backfire. They relied, in large part, on fashion-conscious gay men to sustain their brand. Those sales figures are likely to take a significant dent.

For now, though, we're focusing on the boycott and Thursday's protest, which we believe will have a deservedly damaging impact on Dolce and Gabbana's business. Already many celebrities have announced that they're not going to buy D&G clothes anymore. I'm sure the consumer boycott will swell, and our protest will help give it momentum.

Dolce and Gabbana have a right to express their point of view. We have an equal right to criticise them and to refuse to buy their clothes.