Felbrigg Hall, NorfolkCredit: Getty Images For nearly 40 years, the vibrant rainbow flag of the gay pride movement has come to represent diversity and tolerance. However, a decision by the National Trust to demand 350 of its volunteers at a Jacobean mansion wear the banner or be banished to backroom chores has triggering an angry backlash.Bosses at Felbrigg Hall in Norfolk wrote to their army of volunteers asking them to all wear a lanyard or badge displaying the rainbow flag to welcome lesbian, gay, bisexual, transgender and queer visitors. The email, seen by The Telegraph, reveals that those who refused would not be allowed to meet and greet guests to the 17th Century hall. “To coincide with the campaign we would like staff and volunteers to wear the rainbow lanyards or badges as this is an internationally recognised symbol of inclusivity,” she says.“However, we appreciate that we have not given everyone much time to think about this. Ideally we would have had more time to introduce the programme but this has developed very quickly. “We respect people’s decisions to opt out of wearing the lanyard. If this is the case please come and talk with us and during this period we will ask you not to be on duty in a visitor-facing role. Mike Holmes, who has volunteered there for 13 years, said those in open revolt were not homophobic, but simply annoyed that the Trust had strayed beyond its role as guardian of the country’s heritage.“Wyndham would have turned in his grave to know what’s happening,” Mr Holmes, 72, said. “He was an intensely private man. He was never open about his sexuality.“The National Trust looks after grounds and buildings, they do not have the right to research their benefactor’s private lives to suit the needs of a marketing campaign. It’s abhorrent.“This is not about the squire’s sexuality, I am not homophobic and that’s not what this is about.“I love Felbrigg Hall, and I think nobody could say the volunteers aren’t the greatest advocates for the place. “We do recognise that some volunteers may have conflicting, personal opinions. However whilst volunteering for the National Trust we do request and expect individuals to uphold the values of the organisation. We encourage people with any concerns to chat to our teams.”The rainbow flagwas designed by the San Francisco-based artist and gay rights campaigner, Gilbert Baker, in the late 1970’s.It features up to eight colours – including “hot pink” – which represent sex, life, healing, sunlight, nature, art, serenity and spirit. The move was part of the Trust’s Prejudice and Pride campaign marking 50 years since the decriminalisation of homosexuality. But it was mired in controversy when the Trust “outed” Robert Wyndham Ketton-Cremer, the late owner of the hall, last month in a short film narrated by Stephen Fry.Relatives and godchildren of the country squire wrote to the Telegraph complaining that the “intensely private” historian and poet who died in 1969 should not have been “outed”. Stephen Fry narrated the National Trust programme ‘The Unfinished Portrait’Credit:PA “There’s a group of about 10 of us who have volunteered for more than 10 years, and we’ve now been told that if we don’t toe the line, we can’t do our jobs.“People are getting ill over this, they’re losing sleep because they’re missing out on a big part of their daily lives and doing something they love so much.”Another volunteer, who did not want to be named, said she had not signed up for any shifts during the summer Prejudice and Pride campaign when volunteers and the 48 staff are required to wear the rainbow flag colours. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. It is understood that at least 10 Felbrigg Hall volunteers have refused to wear the lanyards or badges in protest at the Trust’s decision to publicise his sexuality. There’s a group of about 10 of us who have volunteered for more than 10 years, and we’ve now been told that if we don’t toe the line, we can’t do our jobsMike Holmes, National Trust volunteer Robert Wyndham Ketton-Cremer Credit: National Trust By wearing the lanyard we are sending a clear message of welcome to all of our visitors “By wearing the lanyard we are sending a clear message of welcome to all of our visitors.”In a statement, Annabel Smith, the Trusts’ head of volunteering, said staff and volunteers sign up to the organisation’s “core ambition”, adding that the Trust was committed to “promoting equality of opportunity and inclusion”.She said “As part of our ‘Prejudice and Pride’ programme our staff and volunteers are wearing rainbow badges and lanyards, as an international symbol of welcome. An email written by Ella Akinlade, the general manager at the hall, said the use of the lanyard and badge was an attempt to “send a very clear and visible sign to visitors” that they support the LGBTQ community who “shaped” many of the Trust’s properties.