Theresa May has urged Britain to "unite and move forward" after the Brexit vote in her first Christmas message as PM.
In the year that saw the UK vote by 52% to 48% to leave the EU, Mrs May said there was an "historic opportunity" to forge "a bold new role".
However, UKIP's Paul Nuttall used his Christmas message to call for faster progress on Brexit in 2017.
Labour's Jeremy Corbyn highlighted the plight of the homeless while Lib Dem Tim Farron focused on child refugees.
The Green Party urged people to fight for a future based on equality and hope in its Christmas message.
The prime minister said there had been much to celebrate in 2016 - with the Queen's 90th birthday and British successes in the Olympics and Paralympics.
She added: "As we leave the European Union we must seize an historic opportunity to forge a bold new role for ourselves in the world and to unite our country as we move forward into the future."
She pledged to "stand up for the freedom of people of all religions to practise their beliefs in peace and safety" and paid tribute to those who work over Christmas, including health and care workers, emergency services and the armed forces.
"Wherever you are this Christmas, I wish you joy and peace in this season of celebration, along with health and happiness in the year ahead," she said.
In a separate message to the armed forces, including the 5,000 deployed on operations over the holiday period, she said: "Just as your commitment to our country is unfaltering, so in return we owe you the same deep commitment and unflinching support."
She pledged to "honour the commitments" to help service personnel buy their own home and support their children in school.
'End of the line'
UKIP's Paul Nuttall used his first Christmas message since becoming leader to say his top priority would be to ensure "much faster progress" on Brexit.
He warned MPs who attempt to disrupt the process of leaving the EU "will find their prospects for re-election greatly diminished".
Mr Nuttall added that Brexit alone would not be sufficient for the "revival" of the UK to help those forgotten by the "political elite", adding that it was time to reorder the priorities of our governing class.
Labour leader Jeremy Corbyn used his Christmas message, which he posted on Twitter, to point to Shelter figures suggesting 120,000 children would spend Christmas without a home to call their own while rough sleeping had increased by 30% in the last year.
He praised charity workers, adding: "It's the goodwill and generosity of ordinary people, public service and charity workers who give tirelessly to help the most vulnerable and the lonely.
"They remind us of Christmas values: love for your neighbour, working together and hope, hope that things can be different."
In a message filmed at a child refugee centre in Paris and posted on YouTube, Lib Dem leader Tim Farron said the Christmas message should encourage the UK to open its doors.
He said the children were fleeing "appalling circumstances" and wanted to come to the UK "because of Britain's reputation as a place of peace and of security and tranquillity" to start afresh, urging Britons to "be true to British values and be really proud of our country".
The Green Party's newly elected co-leaders, Jonathan Bartley and Caroline Lucas, praised people who worked with refugees and those who campaigned on climate change, as well as NHS workers.
Noting that 2016 had brought the Brexit vote and the election of Donald Trump in the US, Mr Bartley said: "Nobody owns the future.
"Not Donald Trump. Not Nigel Farage. Not Theresa May. We have to fight for the future we want to see - a future based on fairness, on equality, on hope."