Germany is to push for tough data protection controls to be included in a proposed EU-US free trade pact in the latest sign of the growing impact of the outrage triggered by Washington’s mass surveillance and concerns about industrial espionage.

Berlin is to press the European Commission to incorporate data safeguards in the negotiations for the planned Transatlantic Trade and Investment Partnership, launched earlier this year by EU leaders and US President Barack Obama.

The move could prompt a clash with Brussels which fears that introducing privacy rules in the talks could seriously delay or even derail the entire deal. Brussels officials say the development comes as “a big surprise” and follows hot on the heels of a call made last week by Viviane Reding, the EU’s top justice commissioner, to keep privacy rules out of trade talks.