Slaughter and May has won a landmark, multi-billion pound battle in the House of Lords for client Deutsche Morgan Grenfell (DMG) to claim back taxes from HM Revenue and Customs paid before a six-year limitation.

The Lords voted four to one in favour of DMG claiming back interest on Accelerated Corporate Tax paid since 1975.

The decision could open the door for similar claims, possibly costing HM Revenue and Customs billions of pounds.

Laurence Rabinowitz QC at One Essex Court and DMG’s lead counsel said: “The payments go back to the 1970s. The interest on that is enormous. As I understand it there may be billions of pounds worth of claims.”

“In a way, it’s not great news for the tax payer,” he added.

The House of Lords decision overturned a unanimous Court of Appeal decision of Lord Justices Buxton, Rice and Jonathan Parker.

The case has turned out to be lucrative for One Essex Court. The chambers had a silk on each side.

Slaughter and May dispute resolution partner Sarah Lee, advised Deutsche Morgan Grenfell, instructing Laurence Rabinowitz QC and Stephen Elliot at One Essex Court, and Francis Fitzpatrick at 11 New Square.

The HM Revenue and Customs Solicitors Office instructed Ian Glick QC at One Essex Court and David Ewart at Pump Court Tax Chambers

Rabinowitz and Glick will face each other again in the House of Lords next week on the Sempra Metals v HM Revenue & Customs tax case.