The Government’s flagship LGBT conference, which was cancelled after a row over its stance on banning conversion therapy for transgender people, could cost more than half a million pounds, according to official estimates.

The global Safe To Be Me conference was scheduled to take place in London from June 29.

However, it was cancelled in early April after dozens of LGBT+ and HIV groups said they would not take part unless Boris Johnson reverted to his promise for a trans-inclusive ban on conversion therapy.

When the Government initially announced its initial consultation into the conversion therapy ban, its “universal” proposals were intended to protect all LGBT people.

In late March the Prime Minister dramatically dropped plans for legislation, but U-turned within hours following a furious backlash.

However, it was reported that trans people would not be included in the ban, due to “complexities and sensitivities”.

The Government has since outlined legislation in the Queen’s Speech which would ban conversion therapy intended to change someone’s sexual orientation in certain scenarios.

But it said that, due to the “complexity of issues and need for further careful thought”, this will not protect transgender people.

Equalities minister Mike Freer told the House of Commons the Government had incurred production costs of £365,000 by the time it was cancelled.

It is also liable to pay a £200,000 cancellation charge to the venue.

The Government is looking at whether VAT can be recovered on the above costs, so the total may change.

A Stonewall spokesperson said: “The conference was a missed opportunity to help further LGBTQ+ rights around the world and it is a shame that the UK Government’s actions have meant that resources and time have been wasted.

“Trans people are nearly twice as likely to be targeted by conversion practices and it is shameful that the UK Government is choosing to protect some LGBTQIA+ people and not others from this abusive practice.

“We remain in ongoing dialogue with the Government on a range of policy issues, but could not support this conference when the Prime Minister continues to ignore the medical and human rights consensus on the need for a trans-inclusive ban on conversion therapy.”