David Cameron tonight launched an assault on plans for tougher European data protection laws - just as German chancellor Angela Merkel stepped up her campaign against Washington over alleged breaches of her own mobile phone data.
The Prime Minister was making a stand during opening talks at an EU summit in Brussels, arguing that proposals to tighten data rules to increase protection for individuals in a digital world would costs businesses hundreds of millions of pounds a year in extra bureaucracy.
Some small firms might be forced to hire dedicated "data protection officers" just to monitor compliance if the EU Commission plan is adopted by Europe's governments as planned by next April, he said.
But Downing Street officials made clear that Mr Cameron was keen to sidestep involvement in the growing storm - which threatens to overshadow the summit - over German insistence that Washington has been interfering in Mrs Merkel's own data protection rights, by monitoring her calls.
Her complaints are strongly backed by France, which is pursuing its own inquiries with Washington over French newspaper reports that the US National Security Agency has been monitoring the calls of millions of French citizens.
Speculation was mounting as the summit started of a Franco-German push to suspend negotiations on an EU-US trade deal in protest, but a Downing Street spokesman said Mr Cameron would continue to support the initiative, arguing that such a multilateral trade accord with the EU bloc should not be affected by a bilateral disputes involving two member states over the phone monitoring allegations.
"We will push at every opportunity for that (EU-US trade negotiation) to conclude as swiftly as possible and we will do so at every opportunity" said the spokesman.
Mr Cameron, meanwhile, was fighting an uphill struggle to raise support at the summit for at least delaying the data protection plans, to allow more time to consider its impact.
That impact includes an £360 million a year on small and medium-sized firms just to meet the new requirements, says the Government, insisting it has strong business sector backing for what it sees as an unnecessary burden.
That support will be demonstrated in Brussels tomorrow when Mr Cameron parades senior members of his business taskforce at a private meeting with a group of his counterparts from the Netherlands, Italy, Denmark, Finland and Germany.
He will urge their support for rowing back the tide of EU regulation, particularly on the data protection rules, over which Britain does not have a veto.
Tonight a spokesman for European Commission President Jose Manuel Barroso insisted Brussels would be demanding that member states stick to the proposed April 2014 timetable for bringing in the new data protection measures.
A Commission spokesman said the laws were needed to step up data protection for every EU citizen - although he did not mention Mrs Merkel by name.