Boris Johnson's decision to prohibit a Christian group's bus advert which suggested gay people could be helped to change has been upheld.
In a High Court ruling on Friday, the Hon. Mrs Justice Lang said the Mayor did not abuse his position as chairman of Transport for London when he imposed the ban.
The posters read: "Not Gay! Ex-Gay, Post-Gay and Proud. Get over it!"
The Core Issues Trust, the Christian organisation which sponsored the campaign, believes that gay people can be 'reoriented' through therapy and prayer.
The Court ruled the Mayor had acted lawfully, but granted leave to appeal. Although an appeal was 'unlikely to succeed' but deserved to be heard because it involved important issues of freedom of expression.
However, Justice Lang was critical of the process and procedures used by TfL and the London Mayor in coming to their decision to ban the ad.
The judge said that TfL had 'applied its Advertising Policy inconsistently' but said that was 'partially outweighed' by the factors against allowing the advertisement to run.
Judge Lang said this included the fact that they were to be on the side of London buses, becoming 'highly intrusive' and would cause grave offence to many.
She also said it was perceived as homophobic and would increase the risk of prejudice and homophobic attacks. She also ruled the advert was not a contribution to a reasoned debate.
She said TfL had acted in its 'own interests' to avoid causing offence to a section of the public and to avoid criticism and controversy.
The posters were in response to a poster campaign by gay rights group Stonewall, which said: "Some people are gay. Get over it!".
Mike Davidson from the Trust gave his reaction to the verdict to Premier's Marcus Jones on the News Hour:
The judge also ruled against claims by the Core Issue Trust that Boris Johnson's decision was based on electioneering ahead of the mayoral election that was held a number of weeks later.
She said it was 'perfectly proper' for Mr Johnson, as Chair of TfL, to be involved in the decision-making process on the issue.
In a statement to Premier, a TfL spokesperson said:
"The High Court has found that we were right not to run the Core Issues Trust's advertisement as it would have breached Section 149 of the Equality Act 2010.
"The advertisement clearly breached our advertising policy as it contained a controversial message and was likely to cause widespread offence to the public.
"This was borne out by the hugely negative public reaction the advertisement generated, including on social media and newspaper websites.
"We are taking steps to address the Judge's comments regarding our internal processes."
The Core Issue Trust has told Premier it is considering an appeal.