Is it illegal/immoral to reject "chav" tenants

Hey everyone, I just met with prospective tenants and I've got a bad feeling about them. They look like typical "chavs" not to mention they had a pretty bad attitude, when I asked them about their employment status they said they're unemployed and on UC. My main issue is the rent for the house they're viewing is £1450 and the LHA rates in my city for a 3 bed house is £178pw. The house is more than double the LHA rate, I'm concerned my house will turn into a weed grow house as they had that odour. Is it illegal to reject them due to this, I've never had a situation like this.