The deal, expected to only last nine months, means the US can continue to access financial messaging data for its Terrorist Finance Tracking Programme (TFTP).

It also arrives the day before the Lisbon Treaty comes into force, which would have given the European Parliament greater rights to scrutinise it. MEPs have raised concerns over privacy and some questioning the legal validity of any deal struck by the EC.

In 2006 it emerged that the American government had been using emergency powers to secretly scrutinise suspect wire transfers sent over the Swift network as part of efforts to trace and cut off terrorist financing. So far, the program has generated 1450 leads for European governments and 800 to other states, says the EU.

The following year EU ambassadors agreed a deal that allowed the US to access data for counter-terrorism purposes only and to keep any data for a maximum of five years.

However, the same year Swift outlined plans for a re-architecture programme designed to allow intra-European data to be stored only in Europe, and thus out of the reach of US authorities.

Consequently, EU member states gave the presidency a mandate to negotiate an agreement with the United States to ensure the transfer of the data and thereby the continuation of the TFTP.

Under the interim agreement, the decision to authorise transfer of data to the US Treasury will be made by a European judicial authority which must verify the legality of the request. Previously, requests to transfer data were made directly to a private organisation. It also obliges US authorities to share with their EU counterparts TFTP leads.

Austria and Germany were ready to block the agreement last week but, according to press reports, finally decided to abstain.

Although the parliament has been sidelined, the Commission will now put forward a new proposed mandate in early 2010 for a subsequent agreement based on the Lisbon Treaty, giving MEPs a greater say.