The Dowager Duchess of Hamilton, Kay Hamilton, who was married to Angus, the 15th Duke of Hamilton, who died in 2010, said she felt increasingly uncomfortable lending support to the SNP after Holyrood rural economy secretary Fergus Ewing said the Scottish Government would not follow the UK lead.
In a letter to First Minister Nicola Sturgeon and Mr Ewing, Kay Hamilton, an animal rights campaigner, wrote: “I have been a loyal supporter of the SNP for many years, and am disgusted by the decision to oppose the ban.
“It is shaming to Scotland. The main two protectors of animal welfare in Scotland – OneKind and Scotland for Animals – are disgusted. I am patron of both organisations. The British Veterinary Association are also against the transport of live animals.
“I hope to hear that this decision is being overturned. I do not wish to withdraw my membership but will have to do so if this goes ahead.”
The dowager duchess added: “Animals can suffer terrible injuries while being transported – broken bones, dehydration and being in overcrowded conditions for long hours.”
Last month Mr Ewing said the ban would be detrimental to Scottish farmers.
Exports of live animals were estimated to be worth approximately £51 million to the Scottish economy in 2015.
Harry Huyton, director of OneKind, said: “The Scottish Government’s position once again risks positioning Scotland behind England and could result in producers in England using Scotland to circumvent a ban on live exports which could do immeasurable damage to Scotland.”
A Scottish Government spokesman said: “We are not currently considering banning live exports from Scotland. The transport of animals from Scotland is strictly controlled, according to EU rules and standards, to ensure the best possible welfare during journeys.
“Now that the UK Government position is clearer, the Scottish Government supports Defra undertaking a consultation on specific proposals regarding the export of live animals for slaughter to continental Europe. However, we have made it clear any proposals which could create further challenges or difficulties for our farming sector, or put Scottish agriculture at a disadvantage, will not be agreed to.”