Attempts to move Christian traditions to the "margins" of British life have "gone far enough", an MP has said.
Mr Pritchard criticised the "politically correct brigade"
Mark Pritchard said "Christianophobia" of the "politically correct brigade" also ran the risk of Christianity being hijacked by extremist parties.
He said he did not want to criticise people of other faiths, but wanted to "protect the Christian tradition".
But the National Secular Society said Christians in the UK had "nothing to complain about".
Mr Pritchard, Conservative MP for The Wrekin, Shropshire, has called a Westminster debate on Christianophobia for Wednesday.
He told the BBC: "The debate is not about doing God or theocracy. It's about ensuring that the Christian tradition of our nation is recognised.
"If mainstream political parties do not recognise and protect the Christian tradition of this nation then other more extremist parties will.
"If that happens, we are in danger of Christianity being hijacked by these ambitions."
Mr Pritchard said the debate was particularly topical, as recent findings suggested four fifths of schools were not staging Nativity plays this year.
He added: "I'm not saying there shouldn't be choice within theatrical provision on schools. But Christmas time would be a highly appropriate time to do Nativity plays, with its message of hope and love and light.
"This would be a positive contribution for children. This isn't criticising people of other faiths or of no faith.
"Freedom of speech and of religion are fundamental principles of any liberal democracy.
"I hope this debate will put down a marker to the government and public bodies."
Mr Pritchard said many officials and public bodies forgot the work done by Christians in charity, business and public service.
He added: "Some people seem to want to forget the Christian tradition going back to the first century and its contribution to arts, culture and science.
"It's gone far enough. If there are those who want to see the Christian church reduced to the margins in this nation they should have the courage to say so, rather than using the rights of other religions as an excuse."
But Keith Porteous Wood, executive director of the National Secular Society, called Mr Pritchard's debate "a waste of precious parliamentary time".
He added: "Christians have absolutely nothing to complain about in this country."
Mr Porteous Wood cited the fact that 26 bishops sit in the House of Lords and that England has an established church.
He added: "The head of state is a Christian, the prime minister is a Christian and almost all the cabinet are self-identified Christians. How on earth can anyone imagine that Christians are disadvantaged or pushed to the margins?"
Mr Porteous Wood also said: "Christians are not being pushed out of public life, if anything they are over-represented."
The Christianophobia debate, to be held in Westminster Hall, is expected to last about 90 minutes.