What does the law mean by 'discriminating on grounds of sexuality'?

Treating someone less well than other employees because they are, or are believed to be, lesbian, gay, bisexual or heterosexual.

Examples of discrimination would include:

• refusing to employ someone, or dismissing them because they are lesbian, gay or bisexual
• refusing access to training or refusing promotion because of sexual orientation
• denying them benefits the employer provides for other employees like insurance schemes, concessionary travel, invitations to social events for employees' partners (etc).
• giving an unfair reference when someone leaves
• victimising someone by treating them less favourably if they have complained about or alleged discrimination, or given evidence in such a case
• discriminate indirectly. This happens when the employer has made a condition that applies to everyone, but it isn't possible for someone who is lesbian or gay to comply with it so easily

The employer will be liable for discriminatory actions taken by anyone acting on their behalf, whether or not it was done with their knowledge, unless the employer can show that they had tried to prevent such actions.