David Cameron has praised the courage of Britain's armed forces and told them "we are forever in your debt" in a Christmas message to troops.

The Prime Minister said it had been a "momentous" year that had seen the withdrawal of combat troops from Afghanistan as well as commemorations to mark the D-Day landings and the start of the First World War.

In a video to be broadcast on Forces TV in the UK and overseas on BFBS TV and Radio, he told servicemen and women they were "doing our country proud" in the crisis support they provide, including help to tackle Ebola in West Africa, the fight against Islamic State and dealing with floods.

Mr Cameron said: "Wherever you are, you stand for the same things - courage, selflessness, sacrifice.

"These are the values that link the deeds of British personnel over the past century, from the Western Front and the beaches of Normandy, to the deserts of Helmand and beyond.

"And we, everyone in this country, are forever in your debt."

Labour leader Ed Miliband also recorded a message and thanked the troops for their "incredible courage, bravery and sacrifice".

He said: "The whole of Britain is incredibility proud of you and proud of what you do for our country."

"We won't forget, we don't forget, what you do for Britain," he added.

"We are incredibly grateful to you."