MONMOUTH MP David Davies has demanded answers from the Treasury following a complaint from a local resident that important personal information was displayed in the window of an envelope sent to her by HMRC.  Sue Read, from Hereford Road in Monmouth, recently received a routine tax notice. In the window of the envelope, her tax number and National Insurance number were clearly visible alongside her name and address.   She contacted Mr Davies with grave concerns that these details could be enough for someone to steal her identity.   "Identity theft has doubled in the last 12 months and the Government is quite rightly warning people to be on their guard about giving out personal information," said Mr Davies. "However, it is clear the Government is unable to follow its own advice.   Ms Read's complaint comes just six months after the spectacular blunder which saw HMRC lose two computer discs containing the personal details of 25 million people including my own. It is therefore extremely worrying to hear they are now sending out letters clearly displaying information for all the world to see and steal.   "I have written to the Financial Secretary to the Treasury to ask whether she considers this to be in order. I have also suggested that she looks at redesigning all correspondence which is sent out from the tax office to protect personal information and ensure only names and addresses are displayed in the windows of envelopes."