PM: UK my priority in euro crisis
David Cameron is to insist it is his job to "keep Britain safe" whatever the fate of the eurozone.
In a speech to business leaders in Manchester, the PM is expected to say the euro area is at a "crossroads" and could go into "unchartered territory".
Greece's inability to form a government able to push through austerity plans has led to talk of it exiting the euro.
Ben Geoghegan reports.