Sir Malcolm Bruce, whose daughter Caroline was born profoundly deaf, said yesterday it should be supported alongside Welsh, Gaelic and even Cornish.
The Liberal Democrat MP for Gordon in Aberdeenshire said it was a vital component of helping deaf people access education and other services. He said: "We have a quite different attitude to sign language communication from spoken language communication.
"The Department for Work and Pensions did give legal recognition and definition of sign language and it was hailed 10 years ago as a breakthrough.
"But it isn't recognised across Government. They recognise Cornish, as well as Welsh and Gaelic, which get huge resources. And yet sign language, which is an indigenous, created language - indeed invented (here) and yet we are not providing support for this language.
"And yet for some people, it is their only language. I know of no Welsh speaker, no Gaelic speaker and I don't know if there are any Cornish speakers, who don't speak English."
Sir Malcolm said some sign languages do not use English, but remain unsupported by the government.
The MP, who is due to stand down at the next election, has moved a backbench business debate in the House of Commons calling for better support for deaf children and young people.
He has long campaigned on deaf issues.