And a majority of people north of the border also say the UK's controversial Internal Market Bill represents a "power grab" on the Scottish Parliament.
The survey by Survation for the pro-independence Progress Scotland think tank also found that 68% of respondents with an opinion believe that the UK Government will not transfer relevant powers from the EU to the Scottish Parliament and will damage the devolution arrangement, while 32% think that the UK Government will do so and and protect the devolution agreement.
The legislation will see the creation of a UK internal market when the current transition arrangement with the EU expires at the end of the year and the European single market ceases to apply here. It has already proven controversial with UK ministers admitting that it will break international law in some limited areas.
The poll of 2,093 Scots between September 25th and October 5th found that 78% of respondents said that the UK Government breaking international law is unacceptable while only 22% thought it was acceptable if it led to a better trade deal with the EU.
The poll also found that 73% agreed Brexit makes Scottish independence more likely, while 27% disagreed. The impact of the Internal Market Bill on independence voting intentions sees 32% more likely to vote Yes, with 15% more likely to vote No, while 53% say it will make no difference to them.
Progress Scotland managing director Angus Robertson, the former SNP Westminster leader, said: “This poll finds there is overwhelming opposition to the UK government breaking international law and that the Internal Market Bill also will not transfer relevant powers from the EU to the Scottish Parliament.
“Brexit continues to have a significant impact on public opinion with nearly three quarters of people believing the UK government is not doing a good job preparing the country for the future, out of the EU. Meanwhile 67% of respondents believe an independent Scotland should be a full member of the European Union."
The Internal Market legislation will allow the UK Government to set regulations in areas like agriculture and environmental standards, prompting claims that this is tantamount to a "power grab" on the Scottish Parliament which has control over these areas in line with the devolution agreement.
The poll found 59% of respondents believe the Internal Market Bill will lead to a ‘power grab’ of responsibilities held by the Scottish Parliament, while 41% think it will lead to ‘scores of new powers’ coming to the Scottish Parliament. The question elicited a high number of don’t know responses, at 43%.
Fewer than a quarter of Scots (24%) agreed the UK government is "doing a good job" of preparing the country for the future, out of the EU, while 76% disagree .
Other findings from the poll released over the weekend showed that almost two-thirds (64%) of Scots believe that the country would vote independence if there was a referendum tomorrow, while two-thirds of Scots who voted No in 2014 have shifted from this position to either being unsure or supporting independence.