As this is Covid-19 related, i.e. the drop in passenger number, surely the shareholders should be propping up their company? Also, as the company is French, and presumably pays tax on its profits to France, any assistance should be given by the French taxpayer, not the UK one.
If the UK does agree to help out with megabucks then it should be either with relevant and substantial interest rates attached and/or shares in the Company transferred to UK ownership.
SNCF own 55% of the shares. A Quebec based Government sponsored Investment body called Caisse de dépôt et placement du Québec own 30%, Hermes Infrastructure own 10% and Belgium own 5%.
The logic should be that if funding is required for Eurostar then the split should be should be 55% from SNCF, CDPQ 30%, Hermes 10% and Belgium 5%. And not a penny from HM Treasury. If any of these companies don't put their full share up then every penny put in by HM Treasury should be secured on shares given to HM Treasury on the basis of 55% SNCF/30% CDPQ/10% Hermes/5% Belgium at a rate of 2 shares per £1.