Queen Elizabeth II to become Britain's longest reigning monarch: Monarch 'will issue a rare public speech' on day she supersedes Victoria

The Queen seldom gives public speeches, preferring recorded messages such as the Christmas speech or ceremonial speeches such as when opening parliament

Queen Elizabeth II attends a dinner with The Argyll and Sutherland Highlanders, 5th Battalion The Royal Regiment of Scotland at the Caledonian Club on May 30, 2012 in London, England. (Lewis Whyld/WPA-Pool/Getty Images)

The Queen is expected to make a rare public speech thanking her subjects for their support as she celebrates being the country’s longest-reigning monarch on Wednesday.

She seldom makes public speeches, instead preferring pre-recorded addresses such as the Christmas speech, or scripted ceremonial speeches such as at the opening of Parliament or at State banquets.

The Daily Telegraph reports that the Queen will address the nation from a newly built railway station in Tweedbank, near Galashiels.

It is expected that she will speak as she unveils a plaque to officially open the Borders Railway line, to the sound of a brass band. However, a final decision on the nature of the speech will be made next week.

Queen Elizabeth II acceded to the throne aged 25 following the death of her father King George VI on 6 February, 1952. On 9 September she will have reigned for 63 years and seven months.

The record for longest serving monarch had previously been held by Queen Victoria, having reigned for 23,226 days, 16 hours and 23 minutes.