Two visiting legal scholars from Cambridge University said that problems over definitions were common in many countries regarding legislation relating to national security or terrorism.
While declining to comment specifically on the proposed legislation under Article 23 of the Basic Law, Jack Beatson, chairman of the Cambridge law faculty, and Sir David Williams, former vice-chancellor, told of the British experience with the Human Rights Act and anti-terrorism legislation.
Sir David said it was important that political questions were addressed by a government that was politically accountable to the people rather than being left to judicial interpretation.
He said judges in Britain were careful not to become involved in straight political questions. 'That is for the politically and democratically accountable politicians, not the judges who are unelected.'
However, Sir David said judges played an important role in laws relating to human rights simply through the transparency and publicity of the judicial process.
Professor Beatson said: 'Such laws are full of difficulties in getting a balance between protecting against new forms of danger to the state and the existing rights and freedoms of the citizens.'