In a historic vote, the European Parliament this week rejected an agreement between EU governments and the USA that has allowed confidential data about British citizens to be handed over to the American authorities.
SWIFT, the Society for Worldwide Interbank Financial Telecommunication, facilitates trillions of dollars in financial transactions across the world each day.
Until now a temporary agreement between the EU and the USA meant that the US Government had access to SWIFT records.
The US has claimed a need to monitor terrorism financial transactions but other legal routes are available where terrorism is suspected.
MEPs say that they used the new powers they gained under the Lisbon Treaty to insist on a correct approach to data control.
North East Liberal Democrat MEP Fiona Hall said:
"This was a one-sided deal. Data about European citizens was being given to the USA but we do not get similar data in return. Also there were inadequate safeguards in place for the correcting of wrong information.
"If Barack Obama were to propose that the EU take American data unilaterally, such a proposal would be thrown out by the US Congress immediately.
"The European Parliament now has the power to approve or reject international agreements and it is a power MEPs take seriously."
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