The U.K.’s domestic intelligence agency, MI5, topped the list for the best employer for lesbian, gay, bisexual and transgender (LGBT) staff in Britain. The announcement was made Tuesday following a survey by a leading gay rights group.

Over 400 companies participated in the list compiled by Stonewall, which campaigns for LGBT equality across the U.K. MI5 topped Stonewall’s top 100 gay-friendly employers’ list after the survey assessed its staff engagement, career development and other factors, BBC reported.

It was "a great acknowledgement of the continued progress we have made,” MI5 Director General Andrew Parker reportedly said, adding: “Diversity is vital for MI5, not just because it's right that we represent the communities we serve, but because we rely on the skills of the most talented people whoever they are, and wherever they may be.”

The survey revealed that MI5 last year provided staff with quality employment, training, opportunities and support for LGBT employees. The intelligence agency reportedly had a ban on recruiting openly gay men and women until 1991. 

“MI5 have made fantastic strides in creating an inclusive workplace. This is an amazing achievement and demonstrates just how seriously diversity and inclusion is taken,” Ruth Hunt, Stonewall's CEO, said in a statement, according to the Guardian.

Other organizations to top the list included Lloyds Banking Group, the National Assembly for Wales, Pinsent Masons and Leicestershire County Council.