A Christian ‘ex-gay’ charity has won a court appeal over the banning of their adverts on London buses, after questions were raised of Mayor of London Boris Johnson’s alleged interference.

The charity, the Core Issues Trust, believe that Boris Johnson abused his position as Mayor of London in having the adverts pulled from London buses in 2012.

The adverts, a response to Stonewall’s “Some people are gay, get over it!” campaign, said: “Not Gay! Ex-Gay, Post-Gay and Proud. Get over it!”.

The High Court had initially rejected the case, but the charity argued to the Court of Appeal that the decision to ban the ads was influenced by the Mayor due to his 2012 re-election campaign.

After internal emails from the Mayor’s team came to light during the hearing, the Court of Appeal ruled on Monday that the High Court must “reconsider this question in the light of the fresh evidence”.

The court revealed on 12 April 2012, the day the ads were banned, the then Deputy Mayor Richard Barnes sent an internal email which said: “I believe that we should take a strong and immediate line on this and get it them stopped”.

A few minutes later, Guto Harri, Director of External Affairs emailed: “Boris has just instructed TfL to pull the adverts and I’ve briefed The Guardian. Who will break that news in next half hour”.

Today’s ruling means the High Court will have to re-examine the case, to determine if “the decision was instructed by the Mayor or made for an improper purpose”.

A separate argument by the charity, that the ban violated their freedom of expression, was quashed by the courts.

Despite the ruling in favour of the Core Issues Trust, the ban on the advert is still in effect.

Lord Justice Briggs also noted that even if the High Court eventually rules in favour of overturning the ban, Transport for London can “nonetheless lawfully decide again to refuse to accept the Trust’s advertisement”.