No Government should be able to sell off or privatise a public company, or public assets over a certain value, without a referendum. Public companies like the Royal Mail were privatised without asking the British people, and other assets are also sold without the express consent of the public.
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There are concerns that some public companies and assets, like the Royal Mail, have been undervalued before sale and the full value therefore not recouped for the benefit of the public. Privitisation of any public organisation, such as the NHS, and the sale of assets over a certain value, should be put to a public referendum before any government can sanction their sale.