As the Queen led the nation in paying respect to Britain's war dead on Remembrance Sunday the Defence Minister, Bob Ainsworth defended the country's mission in Afghanistan, saying the level of involvement could not be determined by public opinion.
As the death toll among British troops rose to 231, Mr Ainsworth acknowledged that support for the campaign had been "dented" by recent losses.
But he said it was important to "persevere" and "show some resolution", adding: "Failure will be a disaster for us."
A ComRes opinion poll today found that almost two thirds - 64% - now believe that the war is "unwinnable", while a similar proportion - 63% - wanted British troops to be withdrawn as soon as possible.
Speaking to Sky News, the Defence Secretary said: "British public opinion has been dented by the level of losses that we have received but we cannot run a campaign like this off the back of an opinion poll.
"We have to persevere, we have to show some resolution.
"This campaign is directly connected to our safety back here in the United Kingdom and people need to recognise that. Failure will be a disaster for us."
Mr Ainsworth insisted that progress was being made in Afghanistan and said troops on the ground understood the campaign was linked to Britain's national security.
He also said the Afghan government would address fundamental issues such as corruption.
Meanwhile, the Queen, warmly clad in a black coat against the autumn chill, placed the first wreath in the annual event at the Cenotaph in Whitehall.
Skies were threatening but the rain held off as the Queen was followed in placing wreaths by the Duke of Edinburgh, Prince Harry, on behalf of the Prince of Wales who is on an official visit to Canada, and Prince William. More wreaths were also placed by the Duke of York, the Earl of Wessex, the Princess Royal and the Duke of Kent.
They were followed by Prime Minister Gordon Brown, David Cameron, Nick Clegg, foreign secretary David Miliband, high commissioners from Commonwealth countries and defence chiefs. Approximately 7,500 ex-Servicemen and women and 1,600 civilians then took part in a march past the Cenotaph.
The crowd 10 deep on the pavement observed the two minutes silence in perfect quiet at 11am before the wreath-laying event. Their minds were no doubt on the recent losses in Afghanistan, which were referred to frequently last night at the annual Festival of Remembrance at the Royal Albert Hall.
Stuart Gendall, director of corporate communications for The Royal British Legion, said: "It's gone very, very well. It's been a very touching ceremony, it's made all the more poignant that foremost in people's minds are the tragic deaths in Afghanistan.
"I think there are more people here today than other years, and there's a definite emotion in the air, you can really feel it.
"People are marching past remembering their fallen comrades from the Second World War, and people are falling even now in a foreign country, young men of the same age."
He said it was the first time that Prince Harry had placed a wreath on Remembrance Sunday.
The Prince has served in Afghanistan.