David Mundell has claimed the Scottish Government asked David Davis to keep his response to calls for a separate Scottish Brexit deal a secret.
UK ministers rejected a Scottish Government proposal to allow Scotland to stay in the European single market, but no formal response was ever published.
Speaking in the Commons, Mr Mundell said Mr Davis had written to Scottish ministers, but added: “Surprisingly, the Scottish Government asked us not to publish our response.”
A Scottish Government spokesman called the Scottish Secretary’s comments “bizarre” and said the UK government was free to publish the letter. The spokesman added that UK ministers “may try to block its publication in response to a freedom of information request”.