A pre-dawn military rehearsal has been held in preparation for Margaret Thatcher's funeral.

In advance of Wednesday's funeral at St. Paul's Cathedral a flag-draped coffin was carried by horse-drawn carriage Monday to the famous domed cathedral in central London.

Some 700 Armed Forces personnel were in place for the drill.

Officials say the practice was needed to familiarize troops from different service branches with the overall plan.

The funeral of the former U.K. prime minister who died last week will be attended by Queen Elizabeth and numerous foreign dignitaries.

It will be broadcast live on CBC News Network and CBCNews.ca beginning at 5 a.m. ET on Wednesday.