The Survation survey found that once those who neither agreed nor disagreed with the policy were removed, 72 per cent nationally said they supported 20mph – up from 65 per cent in 2017.
But a breakdown of the data showed in Lothian just over 50 per cent either strongly supported or somewhat supported 20mph, 19 per cent neither supported nor opposed it, 9.2 per cent opposed it and 19.3 per cent strongly opposed it.
A bill sponsored by Green MSP Mark Ruskell to replace the current 30mph default speed limit with a 20mph limit is currently going through the Scottish Parliament.
Supporters say 20mph limits have been shown to reduce vehicle speed and reducing speed saves lives.
Edinburgh’s 20mph speed limit on residential and shopping streets covers up 80 per cent of the Capital’s roads.
Edinburgh Tory transport spokesman Nick Cook said: “As one of the few areas in Scotland with actual experience of a blanket 20mph speed limit, it comes as no surprise that Edinburgh and Lothian residents are those most strongly opposed to the Green Party’s misguided push for a one-size-fits-all 20mph speed limit across Scotland.
“Evidence shows such schemes to be neither environmentally friendly or efficient, with slower speeds meaning longer journey times and greater congestion. Data from elsewhere in the UK also suggests broad 20mph schemes produce a reduction in speed of just 1mph.”
But the Greens pointed out the combined “strongly oppose” and “somewhat oppose” figures for Lothian had fallen from 43 per cent in 2017 to 27.5 per cent now. Mr Ruskell said the Capital’s roll-out of the lower speed cap had been a success.
And he said other Edinburgh-specific studies had also shown an increase in support for 20mph limits since they were introduced.
“Unfortunately the vast majority of Scotland has not gone down the same route as Edinburgh and that has meant communities in other areas who want 20mph are told it’s not their council’s policy or it’s not a priority.”
And he said his bill was an opportunity to make Scotland’s roads safer and save lives.
“If it does not go through there will be more child deaths and more life-changing accidents as a result.
“If you restrict 20mph to just outside schools you are not capturing the 80 per cent of accidents that happen elsewhere.”
Edinburgh Green transport spokesman Chas Booth said he was pleased that Scotland as a whole was increasingly seeing the case for the 20mph speed limits pioneered in Edinburgh.
“The benefits in both reducing the number and the severity of crashes is recognised by more and more people, including Lothian residents by a factor of nearly 2:1.”