Law Society president Andrew Caplen will this weekend call for an international 'digital Magna Carta' to arrest the creep of government surveillance.
Caplen will give a speech to the annual American Bar Association convention in Boston asking for renewed efforts to establish a global bill of rights.
The idea has already been mooted by internet creator Sir Tim Berners-Lee and former US vice-president Al Gore (pictured).
Addressing delegates, Caplen will explain how the Society is making a concerted effort to raise the profile of the issue of data protection.
'Legal privilege must be protected from any system of surveillance,' Caplen will say.
The Data Retention and Investigatory Powers Act, which was passed last month, will be hailed as an example of 'sweeping' surveillance powers that extend into non-UK companies such as Microsoft and Facebook.
Caplen will say: 'The Law Society has very serious concerns. We still do not know what justified the use of emergency legislation. A cynic might argue that the process utilised was in order to prevent proper parliamentary and public scrutiny.
'Without any assurances that professional secrecy will be adhered to, should we assume the worst?'
Caplen will also use his platform to call on the international legal community to do more to defend lawyers around the world who face repression for their work in challenging governments.
He will assert that lawyers in many jurisdictions are 'under attack' - a situation which has prompted the Law Society to continue its 'Lawyers for Lawyers' programme to support lawyers who face intimidation for carrying out legal work.
He will say: 'We do not expect that every time we write a letter or publish a statement something will happen. We would like it to - but we know that this will not always be the case.
'However, we consider that it is still worthwhile to show support for our colleague lawyers around the world. And to let their national authorities know that international eyes are watching.
'In recent years we have begun to notice that jurisdictions who would previously have ignored our requests for information have now begun to respond. Progress can be made if we stick at it, if we are firm in our resolve.'