However, less favourable treatment based on the fact that a person is in a close relationship with another individual will not engage this protection.
A recent case illustrates this point and provides a useful reminder about the limits of the Employment Tribunal's ability to strike out discrimination claims before any evidence has been heard.
The Reverend J Gould was employed as a Minister by a church in North London from 1 September 1995, until he was summarily dismissed on 1 August 2016. The Church became aware that Mr Gould was experiencing difficulties in his marriage in 2015. These difficulties were an issue of concern for certain senior members of the church's leadership team and congregation.
Eventually, Mr Gould commenced a sabbatical in March 2016 and efforts were made to mediate between the parties. Mr Gould alleged that resolution had proved impossible because of the unwillingness of certain individuals to accept that he could remain as a Minister when separated from his wife.
Mr Gould did not return to work prior to his dismissal on 1 August.
Mr Gould issued a claim in the Employment Tribunal alleging that his dismissal was discriminatory on the grounds that he had been treated less favourably because of his marital status.
At a preliminary hearing (before any detailed witness evidence had been heard), the claim was struck out. In the employment judge's view, Mr Gould was alleging that he had been dismissed because of the difficulties he was experiencing in his relationship with his wife. The fact that he was married was not a factor and therefore the claim was bound to fail.
Mr Gould's appeal to the Employment Appeal Tribunal (EAT) was successful. The EAT agreed that on the basis of the information in his claim form, it was clear that he was alleging that the reason for his dismissal was a combination of his being married and having marital difficulties.
The claim will now go back the Employment Tribunal to be heard in full.
The case raises some useful points for employers: