The issue is not UK pilots working abroad, nor foreign pilots employed in the UK.
The issue is of non-EU pilots working in the UK when UK pilots are barred from working in the respective countries.
The issue is also about whether, since the UK has many EU citizens working as pilots, the rest of the EU raises artificial barriers to UK pilots in contravention of EU law.
It is, further, whether the UK actively encourages (by means of tax breaks, relaxing of roster rules etc.) airlines to recruit abroad when there are significant numbers of UK pilots looking for work.
The issue is whether the UK government is prepared to put its money where its (fairly considerable) mouth is.