After another bloody week in Afghanistan I stood in the Field of Remembrance by Westminster Abbey and wondered if the war was worth it.

The 60,000 small wooden crosses sent in by the public, each pinned with a red poppy representing the blood of the fallen, tell of a nation always willing to make sacrifices. This year a record number were sent in and, for the first time, there is a section marked Current Conflicts.

Among the crowds gathering on Friday morning to pay their respects after news of a seventh soldier killed in Helmand in seven days, few passed without wiping away a tear. Everyone seemed headed for the section marked War in Afghanistan.

There each cross carries a passport photograph, 229 young men and one woman, 93 of whom died this year. To me, having covered the war for its eight years, some of the names were familiar, guys with whom I had shared a joke or come under Taliban fire. To their families they were beloved husbands, fathers, daughter and sons — many just 18 years old.

It seemed a terrible irony that the symbol of the fallen — a poppy — should be partly what is fuelling and funding this deadly war.

As Big Ben struck 12 o’clock, I watched a young woman kneel and weep. “She lost her boyfriend in Sangin,” said her friend standing nearby. “Isn’t that enough now?”

Also watching was Maureen Ryle, who had come down from Yorkshire with her husband Derek. “It’s horrendous, all these young boys. It’s time we brought them home,” she said.

In a week where one of the policemen being trained by British soldiers to protect his own country turned on his mentors and shot dead five in cold blood, an increasing number of people are asking what we are doing in Afghanistan and whether it is worth it.

Public opposition to the war has risen sharply: in a ComRes survey for the BBC published today, 64% said the war was “unwinnable” and 63% thought British troops should be withdrawn “as soon as possible”. In a YouGov poll last week for Channel 4, 35% of people thought all UK troops should be withdrawn immediately, up from 25% two weeks ago.

On radio phone-in and news programmes, discussion has been of little else. “There is a real chance we will lose this struggle in the bars and front rooms of Britain,” warned Lord Ashdown, the former leader of the Liberal Democrats.

Among those now calling for a “fundamental rethink” is Kim Howells, chairman of the parliamentary intelligence and security committee and a former Foreign Office minister.

Howells last week wrote an article questioning whether spending £2.6 billion a year keeping troops in Afghanistan was the best way to protect national security. He called for a phased withdrawal and more focus on domestic spying.

Times Recommends

• 'New York has lost its edge'
• Copenhagen will fail – and quite right too
• More than 17,000 new underwater species found