A question ! If I had an Irish and a UK passport and the UK leaves the without a deal resulting in 90 days in every 180 for UK citizens and I wanted to spend say 5 months in the E.U. would I leave and return to the UK on my Irish passport or leave and return using a combination of the 2 passports ? I'm not sure how it would work at the UK port of entry if I turn up with an E.U. Passport ?