Taking as an example article 109 of the Maastricht Treaty with particular reference to Protocol J, economic policies are now subject to EU treaties. This reduces the democratic accountability of Westminster.
In financial terms, there would be a financial saving in the net contribution to the EU. At the same time, British Parliament has more say in the allocation of funds to specific projects according to British need, rather than falling within EU guidelines.
Agricultural policy can be directed at British agriculture, rather than being reflective of the Mediterranean vineyards, inferior tobacco farms, olive and tomato growers et alia, and more geared towards British needs, for example dairy farming, Britain being a net importer of dairy products whilst a significant proportion of dairy produce goes to waste.
Health and Safety laws, many embedded in undemocratic Stautory Intruments, impose an inefficiency burden on British firms, especially relative to other EU members whose adherence to EU Directives is lower than in the UK.
Abolition of the Single European Act wold also release us from the binding principle of "Aquis Coomunautaire", which binds European courts to upholding closer EU integration over and above cultural recognition. Imperial measurements, goods designned for British tastes, such as chocolate and sausages, would therefore be removed from being threatened by the march of undemocratic and unnaccountable EU bureaucracy.