Another Conservative MP has attacked plans to encourage schools to include references to gay people in maths, science and geography.

New South Dorset MP Richard Drax said the voluntary lesson plans were “ludicrous” and would impose “questionable sexual standards” on children.

The guidance, drawn up by gay charity Schools Out, encourages schools to use gay people and same-sex parents as examples in instances such as maths problems and why people chose to live in certain cities.

There is no suggestion that the lesson plans will involve talking about sex.

Mr Drax, a former Army officer and journalist, has been married three times. His full name is Richard Grosvenor Plunkett-Ernle-Erle-Drax.

He wrote on his blog: “Yes, if you can believe it, homosexuality will be on the curriculum for students studying maths, geography and science.

“According to the Sunday Telegraph, children as young as four could be included. Apparently, these lessons to ‘celebrate the gay community’ are not compulsory and schools will be left to decide.

“This plan is ludicrous and pushes political correctness to new bounds. I would have thought raising educational standards and teaching our children to read, write and add up is far more important than imposing questionable sexual standards on those too young to understand their equality czars.”

Mr Drax has now removed the entry, which was posted today.

He was criticised by Labour Party gay group LGBT Labour, who suggested he wanted to “slip back to the dark days of Section 28″.

LGBT Labour co-chair James Asser said: “References to same sex relationships in curriculum material are designed to present school children with a realistic picture of modern Britain. This has been standard practice for many years, with for example maths problems using a range of characters that reflect the diversity of the UK today

“It’s astonishing in this day and age that a Tory MP is complaining about giving our children a realistic vision of Britain today.

“After 13 years of progress under Labour, it looks like many Tories seek to slip back to the dark days of Section 28, which alienated generations of young LGBT Britons .”

Earlier this week, Conservative MP Craig Whittaker said schools should be concentrating on core subjects.

“This is not about being homophobic, because there are other schemes around the education which support the LGBT agenda,” he said.

Sue Sanders, of Schools Out, told the Daily Mail: “All we are attempting to do is remind teachers that LGBT people are part of the population and you can include them in most of your lessons when you are thinking inclusively.”