The Keston Institute reports that if adopted, the law will require all missionaries to be registered and allow unregistered religious groups to be banned.
In addition to expected restrictions on many Protestant churches, it will also deny legal registration to all Muslim organisations outside the framework of the Spiritual Administration of Muslims of Kazakhstan.
The law on freedom of conscience and religious organisations has already passed from the lower to the upper house of the Kazakh parliament and if approved on January 31, needs only the signature of President Nazarbayev.
Kazakh officials have justified the move by citing an increased security threat from extreme religious groups.
With registration procedures lacking clear definition, religious groups fear the legislation will be open to abuse and likely to be arbitrarily applied by local officials.
However, the real target of the law is believed to be 'non-traditional' religions other than Sunni Islam and Russian Orthodoxy.
The law also raises the number of people required to register as a religious association from ten to 50 nationals, a process that in the past has led to harassment.
Foreign religious groups will only be able to operate through a central religious centre, religious education for children could be banned and there are a variety of pretexts on which religious associations could be banned.
These include refusal to register, activities which contradict the aims set out in its statute, running youth assemblies and infringement of the laws relating to where religious meetings are held if away from the association's base.
An earlier draft of this legislation was revoked in August 2001 following concerns raised by the international community including the Organization for Security and Cooperation in Europe.
The existing laws governing religion in the country comply with international standards of religious freedom and Kazakhstan was considered to be one of the most liberal of the central Asian states.
Christian Solidarity Worldwide believes that if adopted, this legislation would undermine freedom of worship for all legitimate religious groups and is open to abuse from state officials.
CSW is briefing Parliamentarians and Western foreign ministries at the European Union and the United Nations in a bid to get the legislation stopped in its tracks.
Mervyn Thomas, Chief Executive of Christian Solidarity Worldwide, said: "We understand the concerns of the Kazakh government relating to extremist religious groups, but feel that this legislation is not justifiable and will have a negative impact on many law-abiding and peaceful religious groups.
"We are respectfully calling on the Kazakh government to comply with international standards of religious freedom and to ensure this is upheld in their laws and practices."