One of 600 billboard adverts questioning homophobia in schools that have been displayed across the country has been attacked by vandals.

The poster in the town of Blackburn, was “covered in abusive graffiti,” the Lancashire Telegraph reports.

Advertising space in England, Scotland and Wales was donated to gay equality organisation Stonewall by Titan Outdoor Advertising Ltd.

The message – ‘Some people are gay. Get over it!’ – is displayed in giant, tabloid-style capital letters, on a bright red background.

The campaign, originally designed for schools, was developed in collaboration with 150 secondary school pupils and teachers for Stonewall.

They went on show last week.

“Sadly, the vandalism of a small number of the new Stonewall billboards is a reminder that homophobia still exists in our society and highlights the need to address the issue in schools and in our communities,” said Chris Gibbons, the gay charity’s senior education officer.

“However, we are encouraged by the overwhelmingly positive response we have received to this campaign.

“It’s clear that people think anti-gay discrimination is unacceptable and want schools to tackle homophobic bullying. “

In November 2007 it was launched by television actor John Barrowman as part of Stonewall’s Education for All campaign to tackle homophobic bullying in schools.

The posters, stickers and postcards, distributed to all 5,000 secondary schools across England, were so well-received by pupils and teachers that the message has gone beyond the school gates.