luxembourg britain must commit pay owe european union talk begin future relationship bloc brexit european commission president jean-claude juncker say friday british discover day day new problems reason process take long initially think juncker say speech students native luxembourg find time real compromise far remain financial commitments uk concern able able say european council october move second phase negotiations juncker say pay pay impossible way revenge mood hat british eu tell britain summit next week conclude insufficient progress make talk brussels open negotiations future trade deal london hop press happen summit 'they pay eu 's juncker say britain