It has also been revealed that senior SNP figures, including former cabinet ministers, lobbied finance secretary Derek Mackay with their constituents’ concerns over the proposal.
Opponents say Mr Mackay has been seeking to “spin his way out” of the policy, which could see Scots charged £500 a year for parking at work.
The controversial measure was among the concessions given to the Greens to secure the passage of the government’s budget last month. But it has prompted a backlash among motoring organisations, the public and opposition politicians.
More than 150 pages of official correspondence on it have been released by ministers through Freedom of Information. They show that Conservatives’ concerns, raised in February, over the lack of detail in the plans had prompted government officials to draft a media response which included the line: “We have not yet seen any detail from the Greens on the proposed amendment”.
However, both Mr Mackay and connectivity minister Paul Wheelhouse called for the line to be axed from the government’s ultimate response.
Mr Wheelhouse’s private secretary states in response: “Just one deletion in the background note.”
And Mr Mackay’s private secretary adds: “Mr Mackay removed the same line.”
It also shows Nationalist MSPs have been lobbying Mr Mackay on behalf of constituents over concerns about the plans. Former cabinet secretary Angela Constance, ex-justice minister Annabelle Ewing and backbencher Rona Mackay are among those to have raised concerns.
Ms Constance’s constituent states: “This appears to have been added to the budget late, to get it through Parliament, without really considering how it will affect employers and their employees.”
Scottish Conservative finance spokesman Murdo Fraser said: “It’s no wonder Derek Mackay tried to spin his way out of this disaster right from the very start. It’s the latest shambolic revelation in relation to this ill-judged plan.
“All across Scotland, workers and motorists are furious at this idea, which would hit them for £500 a year.”
A Scottish Government spokesperson said: “We have always been clear that the specifics of any Green Party amendment on the workplace parking levy have still to be developed.
“The amendment, when it does come forward, will be subject to the normal parliamentary scrutiny and approval. Ministers have repeatedly answered questions on the levy in Parliament, both in the chamber and at committee.”