Ed Miliband has paid tribute to the "huge contribution" made by the Armed Forces.
His tweet comes as Armed Forces Day is being celebrated across Britain.
Today we recognise the huge contribution the men & women of our Armed Forces have made to Britain. Thank you. #ArmedForcesDay
Celebrities Stephen Fry, Myleene Klass, Wayne Rooney and Joe Hart have marked Armed Forces Day on Twitter.
The Prime Minister David Cameron, Alex Salmond and the Princess Royal are set to join thousands of visitors at the sixth annual Armed Forces Day.
Crowds will enjoy piping, parades and a display by the world-famous Red Arrows as Britain marks the contribution of servicemen and women past and present in Stirling, Scotland.
There will be entertainment in the form of a parachute display and displays by Typhoon and Tornado jets, with Stirling Castle providing the backdrop.
Armed Forces Day was established in 2009 to honour the country's servicemen and women and their families across the Army, Navy and RAF.
Read Labour leader Ed Miliband's blog to mark Armed Forces Day, as he is set to join thousands at the sixth annual event in Scotland.Read the full story ›
A special rail travel discount for the Armed Forces is to be extended to cover all active volunteer reserves, Prime Minister David Cameron will announce today. The HM Forces railcard will also cover reservists' spouses and children.
Available from next week, the railcard will give reservists a third off fares for family days out and trips to visit friends.
The railway has been supporting the country's serving troops with the forces railcard for over 30 years. In Stirling in Scotland to celebrate Armed Forces Day, Mr Cameron said the extension was "fantastic".
He went on: "I know that the forces railcard is already a huge help to tens of thousands of hard-working troops around the country and this is a further recognition of the increasingly vital role our reserves play in our Armed Forces".
General Sir Peter Wall, who will lead the armed forces review into whether to lift the ban on women serving in combat roles, has said the key issue in determining the outcome would be the "delivery of operational effectiveness".
The review into whether to lift the bar on women joining the infantry and the Royal Armoured Corps was brought forward by Defence Secretary Philip Hammond.
The Ministry of Defence had been required to review its existing policy on the deployment of women by 2018 under EU equality laws.
The former head of the Army, Lord Dannatt, has told ITV News he believes female soldiers should not be allowed to serve in front line roles.
Gen Dannatt, who led the Army from 2006 to 2009, said combat situations in which units attack with "violence, bayonets and machine guns" are "not the right place" for women to be.
Defence Secretary Philip Hammond has said the armed forces must review the role female soldiers can play in combat situations to ensure women know the organisation is "fully open" to them.
Mr Hammond said the reality of the armed forces is "very different" from the "macho image" that he said many continue to apply to it.
But he said the restrictions on women in combat situations is "something we have to look at again", in part because of the "message" it sends to women "who might be looking to join other parts of the military".
It is a move that the head of the army, General Sir Peter Wall, has already suggested might make the armed forces "look more normal" - and it seems Defence Secretary Philip Hammond now agrees.
He has ordered a review of whether women should be allowed into combat to start immediately, and wants a report on his desk by the end of the year.
Earlier he told journalists that if the US, Australia and even France had women in combat roles, it was time for Britain to look at the policy again.
Currently, there are more than 16,000 women in the armed forces but about 30 per cent of roles are closed to them.
The Defence Secretary says he does not envisage the numbers who apply will be that large but suggests it is time to send a signal that the army is open "to all who can meet the standards required".
It is also true that if the change does go ahead next year, it will not harm the Government's attempts to appeal to women voters in the run up to the General Election.
The Ministry of Defence has unveiled a human-sized robotic mannequin that will test chemical protective suits for the armed forces.Read the full story ›