MADRID: Prosecutors in Madrid on Wednesday launched an “urgent” investigation into a conservative association that chartered a bus displaying a large, anti-transgender message to tour Spain, drawing widespread condemnation.

“If you’re born a man, you’re a man, if you’re a woman, you will continue to be so,” read the slogan on the side of the big, orange bus, which started circulating in Madrid on Monday.

Chartered by the HazteOir (“Make yourself heard”) association, the bus was part of the group’s latest campaign against the promotion of gender identity, or the right for a person to feel like and be a man or a woman regardless of their birth sex.

It was bound for other Spanish cities but Madrid authorities made an official complaint over possible “LGBT-phobia,” seizing the vehicle.

Prosecutors in Madrid then launched a probe into the organisation to determine whether the campaign could constitute a “hate crime”, asking a judge to have the vehicle immobilised.

The bus campaign drew widespread criticism.

Javier Maroto, a gay lawmaker for the ruling conservative Popular Party, also slammed a project he labelled a “disgraceful campaign of hate” against people who are lesbian, gay, bisexual or transgender (LGBT).

Gerardo, a 71-year-old retiree who refused to give his surname, said he had come to defend his right to freedom of expression, just like those promoting gender identity in schools or elsewhere.

“We have the right to educate our children according to our thinking, why must they impose their criteria?” he told AFP.

“It doesn’t seem right that they teach our children this type of ideology, that anyone can choose their sex.”

Some 10 semi-autonomous regions in Spain have adopted laws against discrimination of transsexuals.

But activists are calling for a state-level law banning discrimination of people for their sexual orientation or gender identity.

Mane Fernandez Noriega of the State Federation of Lesbians, Gays, Transsexuals and Bisexuals, said in a statement that such a law would “protect us from these types of demonstrations regardless of where we are.”