The Houses of Parliament in Numbers

645 - The number of Members of Parliament (MPs) in the elected House of Commons.

15 - The number of political parties represented in the House of Commons. Five parties have a single representative. Labour currently have 349 MPs, the Conservatives have 193 and the Liberal Democrats have 63.

1605 - The year in which a plot to blow up the Houses of Parliament was thwarted.

36 - The number of barrels of gunpowder that one of the conpirators, Guy Fawkes, was said to have been discovered with, by a party searching the cellars beneath Parliament late in the evening of November 4, 1605.

1834 - The year in which much of the Palace of Westminster was destroyed by fire.

1870 - The year in which the new Palace of Westminster was completed. Neither Charles Barry, the architect responsible for the Gothic building, or Augustus Welby Northmore Pugin, the man who designed much of the Palace's interior, lived to see the completion of the Houses of Parliament.

1918 - The year in which women who met a property criteria were allowed to vote. Ten years later, the Equal Franchise Act (1928), finally gave women the same voting rights as men.

737 - The number of members of the House of Lords, the Upper Chamber.

150 - The number of years since Big Ben, the great bell, in St Stephen's Tower first came into operation. The official Parliament website (parliament.uk) reports that: "The Great Clock started on 31 May, the Great Bell’s strikes were heard for the first time on 11 July and the quarter bells first chimed on 7 September."

1949 - The year in which a flock of birds landed on the minute hand of Big Ben, causing the great timepiece to lose five minutes!

Visitors to London can discover more about the new Palace of Westminster, as the Houses of Parliament is officially known, with the Palace Trail audio guide. Download and away you go. To hear a short extract from the tour please click here.

5 - The number of Walk Talk Tour audio walking tours of London. All five London tours are available in French, German and Spanish.

Buy any Walk Talk Tour and get a second one free by entering the following promotional code in the shopping basket page: BI123.