Introducing an opt-out system for organ donation would be "something akin to a tax imposed by the state" on people's bodies after death, a minister with the Free Church of Scotland insisted.

Reverend Dr Donald MacDonald, a former surgeon, said a bid by a Labour MSP to introduce a "soft" opt-out system in Scotland would mean in effect "that the state claims to have ownership of our bodies after death unless we consciously reject this while alive".

Dr MacDonald suggested instead that increasing the number of nurses who are specially-trained on organ donation and improving education on the issue in schools might be a better way of boosting the number of organs that are made available for transplant.

He made the comments in response to Labour MSP Anne McTaggart's proposed member's bill, which seeks to change the law to introduce an opt-out system.

The proposed Organ and Tissue Donation (Scotland) Bill sets out that all adults would have to register if they did not want their organs to be used for transplant after their death.

After someone died, their family would also be consulted to see if they objected to donation but had failed to register.

The opt-out system would not apply to youngsters under the age of 16, who would continue to be able to opt in as potential donors.

Ms McTaggart said: "The aim of this bill is to introduce a 'soft opt-out' system of posthumous organ donation in Scotland.

"With this reform we could truly tackle the shortage of organs available for transplant in Scotland. This would ultimately save lives.

"Under an opt-out system (just as under the current opt-in system), individuals can decide to donate or not to donate.

"This proposal would not compromise the rights of an individual who objected to organ donation and wanted to make their views known.

"Those who did not wish to be organ donors would have the opportunity to make a clear declaration that they were opposed to the transplantation of their organs, and this decision could not be overturned after death."

Dr MacDonald said that while the free Church supported organ donation and transplantation, it believed that "donation should always be on the basis of a deliberate, well-informed, voluntary decision".

He said: "'Presumed consent in an opt-out system is based on the unfounded assumption that every single person who has not opted out was aware of the opt-out provision and has consciously taken a decision not to opt out.

"This is no consent at all and a donation on this basis is not a donation but something akin to a tax imposed by the state.

"It means that the state claims to have ownership of our bodies after death unless we consciously reject this while alive."

He added: "Following the Alder Hey Children's Hospital scandal, the public is suspicious about removal of organs post-mortem and this type of law might only increase that suspicion and could be counter-productive."

The former surgeon continued: "An important factor in the rise in donor rates is the appointment of specially-trained nurses who liaise with the relatives of patients who are potential donors.

"By removing misunderstandings and giving emotional support at a difficult time, relatives are helped to see the benefits of organ donation for those in need and more readily agree to the procedure."