Poland will reintroduce border controls on its frontiers with fellow European Union nations during the 2012 European football championship, Interior Minister Jacek Cichocki said on Monday.
Cichocki said spot checks would be in place from June 4, four days before the tournament kicks off, and end on July 1, the date of the final in co-host Ukraine.
Border controls were dropped in 2007 when Poland joined Europe's travel-smoothing Schengen zone, which now comprises 26 countries, including several outside the EU.
Schengen members can suspend the free flow of travellers in certain circumstances, notably when large numbers are expected to flood in.
Germany took such a step when it hosted the World Cup in 2006, a move followed at Euro 2008 in Austria and Switzerland.
Poland shares borders with four fellow Schengen and EU members: Germany, the Czech Republic, Slovakia and Lithuania.
Adding an extra layer of complexity at Euro 2012 is the fact that fellow host Ukraine lies on the other side of the EU's tightly-controlled eastern rim.
Ex-communist Poland joined the EU in 2004 and its border controls with former Soviet neighbour Ukraine were further beefed up when it entered the Schengen zone.
That means Polish and EU authorities are having to work out how to cope with huge numbers of fans criss-crossing the bloc's border during Europe's showcase football tournament.
The aim is keep border crossings as fluid as possible while also ensuring that EU entry and security rules are respected - and reimposing internal Schengen checks is seen as a trade-off for softer controls in the external border with Ukraine.