A Brexit vote during a sustained period of low oil prices could further hamper Scotland's ailing economy, according to a think-tank.

The Fraser of Allander Institute said growth over the long-term in Scotland has been "weaker than the UK", almost grinding to a halt in the second and third quarters of last year.

Based at Strathclyde University, the economic think-tank has revised down its forecast for 2016 and 2017, citing continued austerity as one of the main threats to Scotland's economic growth.

Emeritus professor of economics at the university, Brian Ashcroft, said: "With growth slowing further across the UK and even more so in Scotland, now is not the time for the chancellor to adopt more austerity measures which will slow growth further and only worsen the flow of tax revenues to the exchequer."

The report said economic growth in Scotland in the second and third quarters of last year had "almost halted" at 0.1%.

It added the "main reason for the slowdown is the low price of oil, which appears to be having a pervasive net negative effect on Scotland's economic growth leading to a widening of the gap between growth in Scotland and growth in the UK".

The UK as a whole has made a stronger recovery from the "great recession", the report said, with GDP 7.1% above its pre-recession peak compared to 3.1% in Scotland.

On the potential impact of the UK voting to leave the European Union in June's referendum, the report said it is "difficult to imagine that it would help improve Scotland's competitive position with respect to our trade with the EU".

Mr Ashcroft said: "Scottish voters in the referendum on June 23 should not lightly dismiss this warning about the consequences of Brexit for productivity growth in view of the already weak performance of Scottish productivity."

The think-tank has revised its GDP forecast for 2016 down from 2.2% in November to 1.9% in its latest report, stating: "This is mainly driven by apparently slowing income growth, a weakening of previously strong domestic investment growth, and an extension of the expected period in which a low price of oil is likely to be sustained."

Growth is then expected to pick up to 2.2% in 2017 as the "price of oil in particular begins to rise to more favourable levels", although this is down from the previous forecast of 2.5%.

Paul Brewer, of PricewaterhouseCoopers in Scotland, which sponsors the economic commentary, said: "The potential for the forthcoming budget to exert further fiscal tightening, oil price uncertainty and the uncertainty surrounding the potential outcome of the EU referendum together create a difficult environment for business and investor confidence."