Christians must be free to speak about their faith and Christmas without fear, the Prime Minister has said.
Her comments come as a report from the think tank ResPublica warned religious freedoms were being eroded and people had been sacked for living according to their beliefs.
At Prime Minister's Questions, Conservative MP Fiona Bruce warned that Christians have become "fearful" about mentioning their faith in public in case they encounter a backlash.
Theresa May, the daughter of a vicar, said religious tolerance is a fiercely guarded principle in Britain that must be respected.
She added that "our Christian heritage is something we can all be proud of". Mrs May said: "I'm sure that we would all want to ensure that people at work do feel able to speak about their faith, and also be able to speak quite freely about Christmas."