The Prime Minister says he wants to change the fact that many Christians around the world have to celebrate the birth of Jesus in secret.
Boris Johnson has released his Christmas message with a vow to stand with persecuted Christians.
"For them, Christmas Day will be marked in private, in secret, perhaps even in a prison cell," he said. "As Prime Minister, that's something I want to change.
"We stand with Christians everywhere, in solidarity, and will defend your right to practice your faith."
His message comes after he vowed to implement the recommendations of the Foreign Office report into the persecution of Christians around the world earlier this year.
Elsewhere, in his Christmas message, Jeremy Corbyn paid tribute to NHS staff.
He also pointed towards how important the themes of the nativity story were.
"People around the world come together to celebrate the birth of Jesus and his message of love, hope and peace," he said. "That message is more important now than ever."
And in his Christmas message, acting Liberal Democrat leader Sir Ed Davey spoke about his Christian faith.
He said: "As a Christian, for me, it's all about hope. And joy. And love.
"What could possibly represent hope, joy and love better - than a new born baby.
"When I held my first child, in the crook of my arm in Kingston Hospital, just minutes after he'd been born, that was the first time I really understood how my own father and mother must have loved me.
"So you don't actually have to believe in Jesus to recognise that for Christians, Christmas has a deep, profound meaning."