"The best way to protect the economy would be to remain in the Single Market and the Customs Union", the report noted, echoing a statement of First Minister Nicola Sturgeon.
In a speech on Monday, Sturgeon said: "For the sake of jobs, the economy and the next generation, today we are calling on the United Kingdom government to drop its hard Brexit red-lines so that Scotland and the United Kingdom can stay inside the single market and customs union".
"Such impacts should however come as no surprise, as we will be leaving the largest single market in the world of over half a billion people", he said. The lack of any United Kingdom government studies to support its plan to leave the trading bloc means "hard Brexiteers have had their chance and failed", it will say.
Ms Sturgeon added: "It beggars belief the UK Government has not produced any meaningful assessment".
Sturgeon argued that British Prime Minister Theresa May "wants to leave not only the political structures of the EU but come out of the European Economic Area shows just how extreme the United Kingdom government's position is".
The Scottish Government will today publish economic analysis of the most likely Brexit scenarios showing that a soft Brexit inside the single market would be the least damaging option for Scotland.
Monday's report said the only credible outcome of the Brexit negotiations between Brussels and London due to take place this year was for Britain to be a member of the EEA.More news: Hawkeyes rally from 20 down to win in overtime
"There is no option short of EU membership that is as good as being in the EU", First Minister Sturgeon said as she presented an analysis of the economic impact of possible future ties with the bloc.
The Scottish Conservatives urged Sturgeon to make it clear she is no longer pursuing such a deal and called on her to back UK-wide trade and immigration rules.
Under Mr Leonard, Scottish Labour has stuck closely to policy at Westminster, dismissing cross-party efforts to keep the United Kingdom in the single market as a gimmick and criticising the SNP for using Brexit as a "political opportunity" to further their independence ambitions.
She said: "By insisting on hard-line pre-conditions the United Kingdom government is itself closing the doors on what can be achieved in talks with the European Union on the future relationship". But UK voters overall backed leaving.
Meanwhile, Labour has been urged to join a cross-party bid to keep the United Kingdom in the single market and customs union.
Opposition Labour Party leader Jeremy Corbyn has also said Britain should leave the single market.
The SNP, Liberal Democrats, Plaid Cymru and Greens have joined forces to back an amendment to the EU (Withdrawal) Bill when it returns to the Commons this week.