Traditional Mother's and Father's Day cards should not be made in schools, says Relate, the relationship counselling charity. Instead, pupils should make "special person" cards to prevent children from single-parent families or with homosexual parents from feeling isolated, angry and upset.
The comments follow a recent article in the American journal Rethinking Schools in which Sudie Hofmann from St Cloud State university, Minnesota argued that making cards or photo albums "might create feelings of insecurity or even anguish".
Denise Knowles, a family counsellor for Relate, said Dr Hofmann had a valid point given the number of children who came from "reconstituted families".
She said: "We have to be aware now that the word 'family' is a broad term and that we cannot make assumptions.
"So when children are making cards, they should be asked whether they would like to make a card to send to someone special and to think about who that someone is likely to be."
The proposal was dismissed by Steve Sinnott, general secretary of the National Union of Teachers.
He said: "To consider abolishing something that gives great pleasure in order to protect children who probably don't need protecting works on the assumption that teachers have no common sense.
"Teachers are far more intelligent and innovative than these suggestions give them credit for.