Hundreds of strangers have turned out for the funeral of a second world war veteran after undertakers put out an appeal for mourners to attend his service.

Uniformed veterans, teenage air cadets and serving members of the armed forces joined members of the public at the funeral of Harold Jellicoe Percival, known as Coe, who died in a nursing home in Lytham St Annes, near Blackpool in Lancashire, last month.

Percival, who served as ground crew with RAF Bomber Command, never married and had no children, and funeral directors feared no one would attend his cremation on Monday morning.

His death prompted Roland L Whitehead and Daughter funeral directors to make appeals in a local newspaper – calls that were further publicised on social media – for armed service personnel past and present to attend Percival's funeral.

So few people were expected at the service that the pallbearers were expecting to have to stay in the chapel to make up the numbers after carrying in Percival's coffin.

But, after an extraordinary response to the advert on social media, it was standing room only in Lytham crematorium on Monday, with well over 100 mourners paying their respects in the drizzle outside.

Initially, no family members were expected to attend. But after the service, Percival's nephew, Andrew Colyer-Worsell, said the family was overwhelmed by the turnout. "It was very emotional," he said. "It just shows how great the British public are."

Some of those who knew him said Percival would not have relished all the fuss. Photograph: PA

He said his uncle might not have relished the attention during his life. "He would be hiding around the corner right now," said Colyer-Worsell, stressing that Percival was not one to dwell on his past in the war. "He was an old soldier, not a hero: just a veteran who did his duty."

Opening the service after the two-minute Armistice Day silence at 11am, the Rev Alan Clark said he was humbled by the number of people who had come to show their respects. "We marvel at the power of the printed word, whether on paper or on screen," he said.

He went on to quote from the John Donne poem No Man Is An Island: "No man is an island / Entire of itself / Every man is a piece of the continent / A part of the main."

The vicar gave a short eulogy about a man he described as a "very private person – something of a nomad, carrying his possessions in a rucksack".

Janet Wareing, the matron at his nursing home in Lytham, described Percival as "a lovely character, very feisty and independent … [He] knew his own mind. He was very proud of what he achieved."

During the second world war, Percival served with 617 squadron, which carried out the famous dambusters raid to destroy dams in the Ruhr valley in Nazi Germany.

After the war, he worked in Australia, later retiring to England and living at the Alistre Lodge nursing and care home, in Lytham.

He was a distant relative of the former British prime minister Spencer Perceval, who was shot dead by a bankrupt broker, John Bellingham, as he entered the House of Commons in 1812.

Percival's coffin, draped in a union jack, was carried into the chapel to the title music from the Dambusters film. A bugler then played the Last Post.

The congregation, inside and out, sang along as the Lytham community choir performed Jerusalem.

Before the service, Sam Hodson, 21, an air trooper just back from Afghanistan, explained why he had decided to attend. "It's important to show respect for those who put their lives on the line for this country," he said.

Young people were at the Lytham crematorium to honour Percival and his comrades. Photograph: Nigel Roddis/Getty Images

Hayden Carnall, 16, had come with other teenagers from the 177 (Blackpool Airport) Squadron Air Training Corps, taking the morning off college to attend. "We want to pay our respects and support his family," he said.

Stefan Fish, formerly of the 14th/20th Kings Hussars and now a Blackpool palliative care team leader, said he had attended too many funerals with few or no mourners in his new line of work.

"This is the opposite side of the coin," he said, looking around at the crowd. "This isn't really about honouring one man. It's about honouring a whole generation. We owe them a massive debt of gratitude."

Bernard Worsfold, 80, chairman of the local RAF veterans' association, said he had expected to be one of just six people at the funeral – the other five being all from his branch. "The funeral directors had phoned us up seeing if we could get a few people together to come, so of course we did," he said. "I never expected anything like this turnout. I'm really pleased."

He said the association's welfare officer would often visit Percival in his home, and had found him to be a very stubborn man who knew what he wanted. "But," he added, "if you can't have what you want when you're 99, when can you?"

He said Percival might not have appreciated the fuss, though. "I'm not sure whether he would have liked all this," said Worsfold, gesturing at the gathering crowd.

Phil Burton was one of a number of veterans who arrived by motorbike to pay their respects. A member of the Brothers in Arms biking fraternity who served 14 years with the Royal Artillery in Northern Ireland and Bosnia, Burton said he had driven through the rain from Leyland, in the South Ribble.

He agreed that Percival might not have relished the attention. "If you'd asked him, he'd probably not have wanted this. Nobody wants a fuss when they go," he said. "But if he's looking down now, seeing all these people, he'll be thinking: 'The family's come for me.'"