Investment is a commercial activity. Details of future commercial investment in gas import projects can be found in National Grid's latest Ten Year Statement (published in December 2009).
The latest estimates of gas import capacity and demand for gas in the UK for 2010 and each of the next five years can be found in the latest edition of the Energy Markets Outlook (published in December 2009). This can be found on the DECC website at:
http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/markets/outlook/outlook.aspx