According to a report by accountancy firm BDO, Scottish manufacturers need to be shown more support, as the sector experiences “a downturn in activity”. The organisation says that manufacturing is a vital part of the Scottish economy; it is calling for “positive action” to encourage the sector in the forthcoming Emergency Budget.

A spokesman said: “Last year in Scotland, there were 8,550 manufacturing enterprises employing 181,630 people, with a combined turnover of £41,112 million. This makes manufacturing the third-highest sector by turnover (after mining and utilities and retail trades), and the second-highest by employment.”

Martin Gill, head of BDO in Scotland, said: “BDO’s latest monthly Manufacturing Optimism Index found that the sector was at its lowest level since March 2013, so this is an essential part of the Scottish economic mix, which needs to be nurtured and developed.

“Manufacturing can often be ignored by policy makers, but encouraging manufacturing growth is a vital part of maintaining and developing the wider Scottish economy; we need to ensure that it gets all the help and support that it can.”

“For example, there is an opportunity in the forthcoming Budget on 8 July to reduce the rate of National Insurance for manufacturing to stimulate growth. We project that this could create up to 5,069 jobs in Scotland and boost GDP by over £202 million per year.

"The further concern is that we must make Scotland attractive to overseas investors interested in manufacturing. At present, although there are only 400 overseas-owned manufacturing enterprises in Scotland — 4.7% of the Scottish manufacturing sector — they account for 55.8% of the turnover and 32.5% of the employment.

“If any of this relatively small number of firms should find a more favourable tax regime or financial incentives elsewhere, either abroad or elsewhere in the UK, then Scotland could start to experience a real drop in GDP. It is equally important to ensure that Scottish and UK firms continue to find Scotland an attractive base for their manufacturing activities.”