The European Commission is pushing back against prolonged border walls within Europe, urging nine Schengen countries to scrap their long-standing internal passport checks in favor of smarter, high-tech security alternatives.

Poland will reintroduce border checks with Germany starting Monday, escalating a growing dispute between the two neighbors over migration policy and the future of Europe’s Schengen free-movement zone.

Traders are facing increased costs and more paperwork due to Brexit border controls, according to a new report from the independent public spending watchdog.