British Parliamentary Post Office Postal History & First Day Covers
The most desirable covers bearing parliamentary postmarks tend to fall in to two categories:
First we have the philatelic covers, usually first day covers. Over the years many sets of stamps have had a number of FDCs produced using FDI postmarks from either the House of Commons or the House of Lords. The covers that have tended to be most prized among collectors are those where the thematic topic of the stamp issue is relevant to Government, Royalty, Parliamentary events or the City of London although - as with most rules - there are some exceptions.
The other main category for collector interest is the commercial, non-philatelic mail and postmarks posted from Britain's parliamentary post offices. The Parliament.UK website offers a useful, free PDF download detailing much of the history of parliamentary post and postal markings with many illustrations included.
GB Stamp Home Page More GB Stamp Articles