You might not agree with it, but this is what the government's bean counters estimate will happen to some of the country's biggest and most important industries.
The sector, which is worth £13bn of the UK's gross value added (GVA) or 0.8 per cent of the UK's GDP, could be at risk in the event of a Brexit. Nearly half (43 per cent) of the sector's total exports go to the EU.
The Treasury says:
The EU provides a single framework for regulating and improving pharmaceutical products. This ensures a high standard of patient safety, raises productivity through economies of scale and increased competition, and reduces the cost of supplying drugs across the EU. The UK has strong influence over the EU’s regulatory framework for pharmaceuticals, which would be lost under any of the alternative relationships
Ascertaining the impact to the City (and beyond) will be high up on many people's agendas. Financial services contribute slightly more than seven per cent of GDP and employs more than a million people, with around a third of its services exported to the EU.
The Treasury argues that the UK's financial services would suffer from reduced access to the single market, which has been crucial in driving its growth, benefiting from firms based in the US and Switzerland which don't have that access.
But the impact would "vary" across the sector, with wholesale banking, capital markets and investment management, along with the many other firms who trade across European borders or through branches in other member states, likely to see the biggest effect.
This sector contributes £8.7bn to UK GVA, and 47 per cent of exports go to the EU - the Treasury notes it "relies on European supply chains" for its continued success.
The Treasury says:
If the UK was to leave the EU, the aerospace industry would be worse off because of a reduction in access to the Single Market. Full access to the Single Market, particularly the customs union, reduces the administrative cost of transporting goods across borders, cutting costs for businesses, like those in the aerospace sector, that rely on international supply chains.
A particularly emotive area currently, and one which the Treasury argues will suffer greatly if the UK were to leave the EU. The report notes the support it has received from the EU to "press for action against unfair competition", as well as state aid.
The report adds:
As a combined block of 28 member states the EU also has real power and influence to tackle unfair international trading practices. The European Commission is taking action to tackle unfair trade in a number of ways:
• the Commission now has a record 37 measures against steel products
• further EU investigations into steel dumping are currently taking place, including on hot rolled flat products
• for wire rod, organic coated steel and stainless steel flats, duties were followed by a decline of over 90 per cent in Chinese imports
Given the pressure on steel industries across the EU, if the UK were outside the EU, the pressure for tariffs and restrictions from the EU would be a very real risk.
There would be a double-whammy to the automative industry - which contributes £11.6bn to UK GVA and employs 147,000 people directly - if the UK were to leave the EU, the report claims, with cars becoming more expensive, and the supply chain costs rising. It would also suffer from a drop in "enhanced competition" provided by the EU, as well as funding for research.
The professional services industry, which contributes more than £110bn of UK GVA, would be worse off in the wake of a Brexit because "an increase in non-tariff barriers would make trade in this sector more difficult".
Currently the sector benefits from the services directive - which allows professional services firms to trade across borders without barriers - and the fact that professional qualifications are recognised throughout the EU, both of which may cease to apply if the UK leaves the EU.
There will be bad news for startups if the UK votes for Brexit:
Differing national regulatory regimes in areas such as consumer law, copyright, and data would represent a significant hindrance for startups who want to be able to easily offer their services across the EU. The EU is in the process of implementing the Digital Single Market, which modernises the EU framework making it significantly easier for consumers and businesses to take advantage of EU wide opportunities. For example, measures that simplify rules for cross-border online purchases will make it easier for consumers to access the best deals from across Europe, allowing businesses to take advantage of the greater opportunities that digital provides to sell across borders. The developed nature of the digital sector and the leading nature of many of its firms suggest the UK could disproportionately benefit from any liberalisation.
The report also highlights industries that have benefited from "reduced burdens" brought about by EU regulation. They include transport, telecommunications and cosmetics.