The British Court of Appeals on January 23 is hearing the representatives of the Iranian and British governments for a second day about a small part of the British government's debt to Iran for a 1971 cancelled contract to sell Chieftain tanks to Iran.

Iran hopes that the decision of the British Court of Appeals on this small part of the debt will settle the two-decade-long litigation. The full amount of the estimated £400m debt and its interest, Iran hopes, will be paid to Iran if the court rules in its favor. The amount in question is about £20m in interest that Iran is seeking on the original debt.

The British debt to Iran is related to a contract between Britain and the Pahlavi government in 1971 for delivering 1,500 Chieftain tanks and armored vehicles for which Iran paid the full amount at the time. The contract was cancelled after the Shah of Iran was deposed in 1979 and Britain has not refunded the money since then.

Iran's Ambassador to London Hamid Baeidinejad in a tweet on January 19 said the legal process of the case would come to an end if the disputed interest is assigned to Iran and "there will be no excuse for default" from the British government.

Richard Ratcliffe, the husband of the British-Iranian Nazanin Zaghari-Ratcliffe who is serving a five-year sentence in Iran for spying for Britain believes Iran has taken his wife hostage to put pressure on the British government to settle the its debt to Iran.

Mr Ratcliffe who has always maintained his wife is innocent is meeting the British Prime Minister Boris Johnson today, January 23, to ask him help free his wife by settling the debt issue.

According to the Guardian, the former Foreign Office Minister of State for Europe and Americas Sir Alan Duncan who became involved in Ms. Zaghari-Ratcliffe's case proposed to the British government to pay its debt into a new escrow account to overcome U.S. sanctions issues which prevent direct payments to Iran.

Iran can withdraw money from the account in the form of humanitarian aid to avoid violation of the U.S. sanctions if this proposal is accepted. The Foreign Office shelved his plan to resolve the debt issue and help release the 40-year-old jailed British-Iranian mother after he resigned in July last year but the plan is now being reconsidered.