The conspiracy charge related to an alleged attempt to blackmail disgraced former council leader Dame Shirley Porter and her son John.

Boardroom battle

Facing the same charges at Southwark Court was private investigator George Liddell, 46, from Nether Winchendon, Buckinghamshire, who received the same sentence as Stanford.

The pair admitted the interception relating to communications at Redbus Interhouse plc between 22 June 2002 and 18 March 2003.

Stanford had hoped to used "confidential" material in the e-mails in a boardroom battle with John Porter, but realised there was much more wide-ranging material in the e-mails - material which was eventually passed to the council's lawyers and the media.

The e-mails were said to have "triggered" Dame Shirley's decision to settle the multi-million pound "homes-for-votes" charge made against her.

Wealth revealed

She had maintained she could not afford to settle the 15-year scandal as she had only £300,000, but the e-mails showed her wealth to be far greater.

The former Westminster City Council leader was disgraced over a plot to sell off cut-price council houses to potential Tory supporters

Passing sentence Judge Geoffrey Rivlin, QC, said the Crown's case was that Stanford then arranged to intercept e-mails "in the hope that by gaining knowledge of the contact of John Porter and Shirley Porter that might be disadvantageous to them so that you could use that information in furthering your ambitions in relation to Redbus". Protection from hackers

He said it was not the intention of Stanford and Liddell to affect the Westminster Council scandal, but to take over the Redbus company.

You can also check : Top News News of the Week

The judge said: "It is essential people, in whatever walks of life, and, of course, those running important businesses, should know that the integrity of their confidential communication should be respected, and ... they will be protected from being hacked into by outsiders."

Prosecuting lawyer Sarah Whitehouse said Stanford's plan to discredit Mr Porter involved inserting software called a "mirror wall" in Redbus's computer system.

"The effect was that any e-mail sent to Mr Porter's account and members of his staff was automatically copied at the same time to a special account set up by Liddell especially for that purpose."

Stanford appeal

As a result a "vast amount" of private information about Mr Porter, including details of his bank accounts, privileged legal documents, and other material, ended up in the defendants' hands.

After the case Stanford's solicitor Helen McDowell said despite her client's decision to change his earlier not guilty plea and admit the interception charge, he still maintained his innocence.

"Mr Stanford pleaded guilty to this offence following what we regard as an erroneous interpretation on a very complex new statute (the Regulation of Investigatory Powers Act 2000).

"The judge's ruling gave Mr Stanford no option other than to change his plea to one of guilty, and we will be vigorously pursuing an appeal with a view to establishing Mr Stanford's innocence," she added.