In a brief issued Tuesday, the ICJ notes that some of the most significant human-rights treaties required ratifications by 20 or even fewer signatories before they could take effect. The 1948 Genocide Convention required 20 ratifications, as did the 1973 convention against apartheid, the 1984 Convention against Torture and the 1989 Convention on the Rights of the Child.

The International Covenant on Civil and Political Rights and its companion, the International Covenant on Economic, Social and Cultural Rights - both of which took effect in 1966 - were at the high end of the spectrum, requiring 35 ratifications each.

"Given the trend in human rights treaties to require a relatively small number of ratifications, the ICJ believes that it would be reasonable to require no more than 20 to 25 ratifications," the brief states.

Many countries, however, are looking toward a higher figure in order to ensure the "universality" of the Court. British foreign ministry official Tony Lloyd indicated recently that the Court could enter into force if some 50 countries accept its authority; other countries want the bar raised even higher.

Setting too high a level, however, would cause significant delays in establishing the Court, some activists warn. Many experts believe that, even with a relatively low number of ratifications, the ICC statute likely will not enter into force - and the Court will not be set up - for at least three to five years.

In its brief, the ICJ also argues that a preparatory commission be set up among state parties to the ICC statute "as soon as possible", and preferably when the statute has attracted about half the number of signatures or ratifications needed for its entry into force.

The ICJ also recommends that there be no reservations allowed for provisions of the treaty, arguing that "to add reservations would create an undue imbalance to the whole system and would impair the uniformity of obligations". It says countries should secure a "high majority of every state party" before they could amend the text.