Funeral for Britain's Iron Lady underway in London

LONDON (AP) - The Iron Lady is being laid to rest on Wednesday, as world leaders and dignitaries from 170 countries gather in London to attend the funeral of former British Prime Minister Margaret Thatcher on Wednesday

The funeral, an elaborate affair with full military honours, will culminate in a service at St. Paul's Cathedral in the city.

Dozens of people camped out overnight near the 17th-century cathedral in hopes of catching a glimpse of Lady Thatcher's flag-draped coffin and its military escort, and hundreds had arrived hours before the funeral was due to start.

"I came to commemorate the greatest hero of our modern age," said 25-year-old Anthony Boutall, clutching a blue rose. "She took a nation on its knees and breathed new life into it."

Flags on government buildings were lowered to half-staff across the country ahead of the service, but not all Britons were joining in the mourning.

Hundreds of political opponents said they would stage a silent protest by turning their backs as the coffin goes by, and retired teacher Henry Page stood outside the cathedral on Wednesday morning bearing a sign in protest at the funeral's reported US$15 million (S$18.5 million) cost - "Over 10 million pounds of our money for a Tory funeral!"

A coffin bearing the former leader's body will travel by hearse from the Houses of Parliament to the church of St. Clement Danes, before being borne on a horse-drawn gun carriage to the cathedral, where 2,300 invited guests will await.

More than 700 soldiers, sailors and air force personnel will line the route and around 4,000 police officers will be on duty as part of a major security operation, stepped up after Monday's bombings at the Boston Marathon that killed three people and wounded more than 170.

The woman nicknamed the Iron Lady transformed Britain during her 11-year tenure from 1979 to 1990, and died on April 8 at age 87.

Mrs Thatcher is being given a ceremonial funeral - not officially a state funeral, which requires a vote in Parliament. Still, the proceedings will feature the same level of pomp and honour afforded to Princess Diana in 1997 and the Queen Mother Elizabeth in 2002.

That has raised the ire of some Britons, those who believe her legacy is a socially and economically divided nation. Scotland Yard says it is working with a "small number of people planning to protest" peacefully on Wednesday.

Prime Minister David Cameron said the ceremony was "a fitting tribute to a great prime minister respected around the world." The dean of St. Paul's, David Ison, has acknowledged the funeral has divided opinion, but said the service itself would be a somber affair.

"There is no tribute," he said. "There is no eulogy, and that was Mrs Thatcher's decision. It's not being triumphalist. It's not a celebration of her life and her achievements."

Those attending the Thatcher funeral include Queen Elizabeth II and her husband Prince Philip, 11 prime ministers from around the world, former US Secretary of State Henry Kissinger and former US Vice President Dick Cheney.

Some high profile guests sent their regrets: Former First Lady Nancy Reagan - whose husband Ronald had a close relationship with Mrs Thatcher - will not be able to attend; nor will former Soviet leader Mikhail Gorbachev, who shared key moments in history with the late prime minister. Germany's Angela Merkel sent her foreign minister, while the American political power families the Clintons and the Bushes declined to attend.