"The United Kingdom's policy is to allow gay men and lesbians to serve openly, and discrimination on a sexual orientation basis is forbidden.
It is also forbidden for someone to pressure LGBT people to come out."
Wiki

Gay Britons Serve in Military With Little Fuss, as Predicted Discord Does Not Oc NY Times May 21, 2007

"Since the British military began allowing homosexuals to serve in the armed forces in 2000, none of its fears — about harassment, discord, blackmail, bullying or an erosion of unit cohesion or military effectiveness — have come to pass, according to the Ministry of Defense, current and former members of the services and academics specializing in the military.
The biggest news about the policy, they say, is that there is no news.
It has for the most part become a nonissue."

General Sir Richard Dannatt, the chief of the general staff, told members of the Army-sponsored Fourth Joint Conference on Lesbian, Gay, Bisexual and Transexual Matters that homosexuals were welcome to serve in the Army.

In a speech to a conference in London in October last year, – the first of its kind by any Army chief – Gen Sir Richard said that respect for gays, lesbian, bi-sexual and trans-sexual officers and soldiers was now "a command responsibility" and was vital for "operational effectiveness".

He also added "We have made real progress in our understanding of equality and diversity in the military context, and there is a desire to achieve more yet.
My recent Equality and Diversity Directive for the Army sets the standard that we must live by, and, importantly, it communicates that standard to everyone in the chain of command.

"Respect for Others", one of the Army's core values, is at the heart of this directive."