UK's GDP for 2012 in the Blue Book

http://www.ons.gov.uk/ons/rel/naa1-rd/united-kingdom-national-accounts/the-blue-book--2012-edition/index.html

GDP - Blue book 2011

The official document charting the total value of all the goods and services produced in the UK economy:

http://www.ons.gov.uk/ons/rel/naa1-rd/united-kingdom-national-accounts/2011-edition/index.html

2010 GDP figures from Blue Book

http://www.statistics.gov.uk/downloads/theme_economy/bluebook2010.pdf