A CONVICTED murderer and former millionaire car dealer has enjoyed mixed success after taking on the taxman from his prison cell.

Ian Workman, who built up the IGW Group in Bolton and Blackburn over nearly 30 years, is currently serving a life sentence after stabbing his wife Sue through the heart at their luxury home in Edgworth in April 2011.

But the businessman, who was told by Mr Justice Clarke he would have to serve 17-and-a-half years before being considered for parole, had lodged a complicated VAT claim for his outfit.

And a ruling has now been issued on the £310, 563 claim by a Tax Chamber judge, after Workman gave evidence to the tribunal via a video link.

Workman insisted he was owed the money in overpayments, using established case law covering motor traders being incorrectly charged VAT by HM Revenue and Customs on demonstrator vehicles and manufacturers bonuses.

The tribunal heard the taxman would only accept Workman and the IGW Group, or its predecessor Mossweald, had used 76 vehicles a year, between 1979 and 1996, as demonstrators, vehicles for employees and directors, or courtesy or hire cars.

But Workman, who was represented at the tribunal by counsel Tim Brown, claimed that figure should be 316, based on the cars being changed four times a year.

Giving evidence Workman said Mitsubishi, Suzuki and Hyundai demonstrators were replaced every three months and the old demonstrators were sold. Renault Scimitar demonstrators were replaced every four months.

The salesforce were tasked to find customers in advance of demonstrators coming to the end of their three-month life, he told the hearing.

Workman said targets were set for sales staff on a quarterly basis and that this would include replacement of demonstrators.

Judge Jonathan Cannan ruled that 111 cars would have been eligible, as part of the claim, when the business was at its peak in 1994-95.

He told the tribunal his figures were based on the vehicles being replaced three times a year, and not four, as Workman had contended, and he could not follow why 30 courtesy vehicles were required for the bodyshop so reduced that figure to 15.

Judge Cannan added: "I am satisfied that Mr Workman was very knowledgeable about the business generally. That is to be expected, as he was the driving force behind IGW Group.

"However, the facts I am asked to find are specific details rather than generalities."

The case is not the first time Workman has been embroiled in legal proceedings since his 2011 incarceration.

Three years ago he was ordered to pay two of his sons, Ben and Nicholas, £1.5million after he had killed their mother during a divorce row to avoid paying her half of his fortune.