Since the UK has no right to Galileo as a third country, a better tactic would have been to get on their knees, beg, grovel and generally make whining noises....
The UK has made way too many false statements and unfounded demands:
1) the UK was not central to the UK project. The Galileo projects were managed under a scheme called "juste retour". This scheme ensures that if the UK invests 1 bn euros in Galileo, then it has already received that exact same amount in Galileo contracts to UK companies, even if it is not a major integrator of ESA satellites (which it isn't) or developer of Galileo payloads (which it didn't). While France, Italy and Germany have all integrated the larger ESA satellites over the past decades, the UK has only now inaugurated a large integration facility in Harwell (which at this point may never be used). Having already received 1 bn in contracts, the threat of asking for money back is only going to get the UK kicked further out of the project.
2) the Uk's main role was the integration of Galileo payloads (developed by others). This is a relatively easy role to replace. Not only is the 3 year+1billion extra cost total nonsense, but because the UK only got those tasks under "juste retour", countries such as Spain will be able to do a better job at half the price.
3) This article mentions the UK working with AUS and NZ on an alternative GPS system. Does anyone realize how silly this sounds? Is the UK trying to gain the EUs sympathy by making them piss themselves with laughter?