Vince Cable’s office has for months put hundreds of his constituents at risk of identity fraud by carelessly dumping sensitive papers and letters.

The Business Secretary’s staff casually ditched un-shredded documents that revealed residents’ private information, including medical records, visa applications, financial affairs and legal cases.

The shocking revelation will raise serious questions about data protection and confidentiality at his constituency office in Lion Road, Twickenham.

The discarded documents include hundreds of constituents’ full names, addresses and phone numbers, with some containing other data such as national insurance numbers.

In one private letter a father, living in Twickenham, pleads to Dr Cable for help freeing his son, who is in detention in Dover.

He threatens to kill himself because of his problems with immigration officials.

Another correspondence reveals medical information about a named mental health patient, and the hospital and ward in which he stayed, along with his application for housing.

Dr Cable’s office had ripped up a small amount of the paperwork before throwing it into clear plastic bags, but most of the documents were whole and none were shredded – despite the Government advising this as best practice.

One 25-page list, dated October 14, 2011, clearly shows the personal data of about 300 residents, including their addresses, mobile phone numbers and email addresses.

Spreadsheets also reveal the political persuasions of constituents in Coombe Crescent, Hampton North, and in Marble Hill Close, Twickenham.

Sensitive letters include a reply from Nick Whitfield, director of education at Richmond Council, about a parent’s primary school application. Another from a solicitors’ firm – marked “private and confidential” – reveals personal data about a client.

Other documents discuss the parking problems of residents suffering from multiple sclerosis and incontinence.

The chief executive of NHS Richmond wrote to the Twickenham MP, naming constituents who have had issues with the primary care trust and Dr Cable also contacted Detective Superintendent David Poole, of Thames Valley Police, about a criminal investigation into a bank, which he names in the letter.

Among the papers carelessly discarded was a letter confirming Vincent Cable MP as a data controller and office manager Joan Bennett as his Lion Road office contact.

Although the letter showed Dr Cable’s controller certification expired on March 28, 2011 it has clearly since been renewed as a search on the Information Commissioner’s Office website shows the MP’s registration for the role does not expire until March 28, 2012.

It also shows that Dr Cable has been a registered data controller for four years since being certified on March 29, 2007.

The inability of Vince Cable’s office to pay bills on time was among inner secrets of his constituency office revealed through his rubbish.

A letter from telephone service provider BT warned the MP his Lion Road office was on the verge of having phonelines immediately disconnected as he had not paid his bills.

The letter dated February 22, 2011, is entitled “Urgent overdue bills – disconnection now due” and refers to an attempt to contact the office about unpaid bills several times and the incurring of late payment charges.

It reads: “You now risk immediate disconnection as specified in the terms and conditions of service.”

The amount due at the time of the late phone bill payment letter was £83.53.

There was also a note from a member of staff attached to the BT bill asking for cheques to be signed off to pay Thames Water and IOC bills.

The handwritten note read: “Urgent. Vince can you let me have cheques for Thames Water £29.11, BT £83.53, IOC £35.50. Thank you.”

One enthusiastic autograph hunter will be disappointed to hear his request for a signed picture of Twickenham’s well known MP ended up in the bin.

The retired welfare and security officer, from Cumbria, went to the effort of getting a blown up head shot of Dr Cable produced and sending it to the Business Secretary’s constituency office in the hopes of having the picture signed for his collection.

He wrote: “Since I retired.... I have been able to pursue my hobby of collecting autographs.

“I have a small collection of signatures from PMs and MPs past and present.

“I would be honoured if you would sign the enclosed photograph and return it to add to my album.”

Unfortunately the request ended up taken out with the trash.