A pastor who opposes gay marriage and believes relationship and sex education is “sexualising” children has been invited to speak in parliament by the DUP’s leader at Westminster.

The Rev Lynda Rose is expected to warn that relationship and sex education (RSE) in schools has been “taken over by ideologues and special interest groups who wish to promote their own agendas” when she speaks at a meeting of the Lords and Commons Family and Child Protection Group.

The group was prominent in the campaign that backed Section 28, which effectively banned teaching about gay relationships in the 1980s, and is chaired by Sir Jeffrey Donaldson, the DUP’s most senior MP.

Representatives of the campaign group Transgender Trend, which has raised concerns about lessons covering gender