Media playback is unsupported on your device Media caption Reeta Chakrabarti reports

A military rehearsal of Baroness Thatcher's funeral procession has taken place in central London.

More than 700 members of the armed forces drawn from all three services took part in the practice before dawn.

They will line the route of the funeral procession from Westminster to St Paul's Cathedral on Wednesday.

Lady Thatcher's coffin is to be carried in a gun carriage drawn by the King's Troop Royal Horse Artillery, which was involved in the rehearsal.

The government has announced that the chimes of Big Ben will fall silent during the funeral as a mark of respect.

Final portrait

Maj Andrew Chatburn, the man in charge of choreographing the parade, said the rehearsal had gone "very well" and it was "vitally important" to stage a trial of Wednesday's event.

"Timings are most important," he said.

Maj Chatburn, ceremonial staff officer for the Household Division, who was also behind the royal wedding procession two years ago and last year's Diamond Jubilee parade, added: "Bearing in mind these are sailors, soldiers and airmen who have come in to do this specific task from their routine duties, so it's new to them.

"They need to see the ground as well so they can get a feel for how it's going to go and they can perform their duties with confidence on the day."

The procession band played the funeral marches of Chopin, Beethoven and Mendelssohn as it made its way along the deserted streets for the rehearsal.

Image caption Members of the Royal Navy lined the approach to St Paul's Cathedral just as the sun was coming up

The Chelsea Pensioners from Royal Hospital Chelsea did not take part due to the early start, but they will line the west steps of St Paul's for the real event.

It has emerged that the last portrait of Lady Thatcher shows her relaxing on a deckchair in the garden of London's Royal Hospital Chelsea, a retirement and nursing home for ex-British soldiers. She was a strong supporter of the Chelsea Pensioners.

The BBC's Ben Ando watched the rehearsal and said it was for the benefit of the service personnel taking part.

Scotland Yard's preparations are ongoing, he added, and the force says the security operation on the day will be in line with the perceived threat level.

Lady Thatcher, who died at the age of 87 on 8 April, has been accorded a ceremonial funeral with military honours, one step down from a state funeral.

On Wednesday, the former prime minister's coffin will initially travel by hearse from the Palace of Westminster to the Church of St Clement Danes - the Central Church of the RAF - on the Strand.

It will then be transferred to the gun carriage and taken in procession to St Paul's Cathedral.

St Paul's Cathedral has published a full funeral order of service.

'Tidal wave of guff'

Respect MP George Galloway has said he will try to block plans designed to allow MPs to attend Lady Thatcher's funeral.

Media playback is unsupported on your device Media caption Respect MP George Galloway says there has been "unnecessary fawning" over Lady Thatcher

Ministers want to cancel Prime Minister's Questions and delay the start of parliamentary business - an approach backed by Labour.

But Mr Galloway has said he will object on Monday evening when the motion is being read.

Under Commons rules, if one MP shouts "object", the proposal would then have to be withdrawn, or MPs would have to hold a debate followed by a vote.

Speaking on the BBC's Daily Politics Show, he said it was "absurd" to cancel PMQs, especially after the cost of recalling Parliament during the Easter break to pay tribute to Lady Thatcher.

He said Lady Thatcher had "laid waste to industrial Britain" and "there are millions of people in this country who hate the very word Thatcher".

These people were not being reflected in media coverage, and were instead being subjected to "a tidal wave of guff", he added.

On Sunday, a song at the centre of an online campaign by opponents of Baroness Thatcher, reached number two after selling 52,605 copies.

The 51-second song, Ding Dong! The Witch Is Dead from the Wizard of Oz film, was not played on BBC Radio 1's Official Chart Show.

Instead, presenter Jameela Jamil linked to a Newsbeat reporter who explained why the song was in the chart.

The news report - which included a brief snippet of the song - also included two views from members of the public on the controversy, with one saying it was "quite funny", while the other said it was "disgraceful".