Stonewall has launched a new high-profile advertising campaign to eradicate workplace homophobia “once and for all”.

Featuring two people at work, the campaign states clearly that: “One is gay. If that bothers people, our work continues.”

Separate posters also include the message: “One is bisexual. If that bothers people, our work continues.”

The adverts will appear on nearly 650 buses in London, Cardiff and Edinburgh as well as on 4,000 adverts on the London Underground.

The campaign comes in response to YouGov polling which shows that in the last five years 2.4m people of working age have witnessed verbal homophobic bullying at work. A further 800,000 people of working age have witnessed physical homophobic bullying at work. Further polling shows that over a quarter of gay, bisexual and lesbian people are not at all open to colleagues about their sexual orientation.

Stonewall Deputy Chief Executive Laura Doughty: “After securing equal marriage in England and Wales people mustn’t forget the huge amount of work still to be done. No one should be under any illusion that it’s ‘Mission Accomplished’. In workplaces right across the country, gay people still don’t feel able to be themselves. It’s time to change that once and for all.”

In September, Stonewall dismissed criticism regarding its rainbow laces campaign against homophobia in football after several Premier League clubs said they wouldn’t be able to support it because of the involvement of Paddy Power.

The campaign was based on distributing and encouraging footballers across all 134 professional clubs in the UK to wear rainbow laces at matches.

However, Manchester United, Tottenham and Norwich refused to back the rainbow laces project because they believe it amounts to an advertising campaign for the bookmaker.

Football v Homophobia (FvH) criticised the “Right Behind Gay Footballers” slogan as relying on “sexualised innuendo and stereotypes about gay men”

But the Gay Football Supporters’ Network (GSFN) applauded the initiative, which had the support of several football stars including Queens Park Ranger star Joey Barton.

Paddy Power was previously criticised for using transphobic stereotypes in adverts to promote betting during the Cheltenham Racing Festival.