On October 21, 2005, the United Nations Human Rights Committee found the Sri Lankan Supreme Court's decision in the Sisters of the Holy Cross in Menzingen (see below) to be in violation of Articles 18 and 26 of the International Covenant of Civil and Political Rights, stating that:

differential treatment in the conferral of a benefit by the State must be provided without discrimination on the basis of religious belief. The failure to do so in the present case thus amounts to a violation of the right in Article 26 (ICCPR) to be free from discrimination on the basis of religious belief.
As a signatory to the ICCPR's optional protocols on enforcement, this decision (available here) is binding law on Sri Lanka.

The Sri Lankan Supreme Court has made determinations on three cases involving religious liberty (all PDF format):

Some important excerpts from the Menzingen Sisters case:

“[T]he constitution does not recognize a fundamental right to propagate a religion.”

“[T]he propagation and spreading of Christianity . . . would impair the very existence of Buddhism.”

The New Wine Harvest Ministries case had the same basic facts as the Menzingen Sisters and the same result:

"[T]he process of uplifting the socio-economic conditions of the people of Sri Lanka, not restricted to persons who are of the same religious belief or faith . . . would necessarily result in an inconsistency with the free exercise of a person's thought, conscience and religion as postulated in Article 10 of the Constitution. The allurement which would result in the process of uplifting socioeconomic conditions would distort the freedom which every person should have to observe a religion or belief of his choice as guaranteed by Article 10 of the Constitution."

On July 23, The Becket Fund sent a legal memorandum (PDF format, 222K) to the Sri Lankan president and prime minister. This memo is a detailed legal analysis of the anti-proselytization and anti-conversion bills now pending before the Parliament of Sri Lanka. It concludes that the enactment of either bill would represent an egregious violation of the freedom of religion, expression, and assembly of Sri Lankan citizens under the country's various, enforceable international treaty obligations.

Emilie Kao, The Becket Fund's Director of International Advocacy, gave a speech (PDF format, 188K) to the United Nations Commission on Human Rights, 60th Session, on April 8, 2004, on the plight of Christians in Sri Lanka.

Supreme Court of Sri Lanka determination on constitutionality of anti-conversion bill (PDF format)

National Christian Evangelical Alliance of Sri Lanka summary of Supreme Court determination

National Christian Evangelical Alliance of Sri Lanka update following Supreme Court determination

Centre for Policy Alternatives petition to the Supreme Court

Centre for Policy Alternatives written statement to the Supreme Court

Solidarity for Religious Freedom petition to the Supreme Court

The Menzingen Determination and the Supreme Court: A Liberal Critique by Asanga Welikala