Brexit could spark a "new era of economic and industrial decline" in Scotland that the country would take a generation to recover from, a union has warned.

GMB Scotland secretary Gary Smith spoke out as economic research for the union suggested nearly 144,000 jobs north of the border were linked to EU demand for Scottish exports.

The report found "for Scotland the best Brexit would be no Brexit at all", Smith said.

READ MORE: Why being patient on indyref2 is hard, but winning is critical

He spoke after experts at the Fraser of Allander Institute economic think tank found that in 2015 nearly 4% of Scotland's employment, excluding public-sector administration and defence, was supported by trade with the EU.

That proportion was significantly higher in some sectors, with more than 14% of manufacturing jobs linked directly to EU export demand, while in computer, electrical and optical products the figure was even higher at more than 23%.

In refined petroleum, chemical and pharmaceutical products it reached almost 30%.

The report noted: "This is not to say that post-Brexit these jobs will be lost (or even reduced).

"It is simply to highlight the current degree of integration that exists between Scotland and Europe in terms of exports."

READ MORE: Mundell admits what we already know: no deal will lead to indyref2

It warned leaving the EU would "represent the most significant change to the Scottish economy in a generation", adding its research indicated there could be "a significant negative hit to Scotland's long-term economic output and jobs compared to a scenario where the UK remained in the EU".

As Scotland's principal international trading partner, the EU was the destination for more than 45% of international exports in 2017 - with £14.9 billion of goods and services sold to other European nations.

The research follows an earlier study the think tank carried out for the union in November 2017, with the latest study suggesting since then 9,000 more jobs in Scotland are linked to trade with the EU.

Smith said: "Let's be clear that for Scotland the best Brexit would be no Brexit at all but in absence of that there needs to be an honest analysis of our future prospects.

"Scotland's economic and employment interdependence with the EU has actually increased and irrespective of what form the UK's withdrawal looks like in the final analysis, it will be detrimental to jobs and prosperity across the country.

"These are the hard facts facing Scotland so this week we should not entertain any nonsense from Brexit cheerleaders about 'taking back control' or a 'jobs first Brexit' - even at the 11th hour the very least those driving us over the cliff-edge can do is tell the truth.

"The price of this political failure will likely be measured in divestment, redundancies and closures across Scotland - a new era of economic and industrial decline that will take hold over the next few years and take a generation from which to recover."