Should UK taxpayers help to bail out the Greek economy?

This country is not in the euro-zone and we kept sterling because of very real fears about poor economic development in countries like Greece. Portugal, Spain and Ireland are also on very shaky ground. Angela Merkel is insisting that all the 27 states of europe should contribute. Greece will require �50 billion over the next year. If contributions are based on GDP, Britain could be potentially ordered to stump up �3.5 billion. We don't even have a veto on this anymore due to signing away our rights under the Lisbon Treaty.