The concerns were expressed as a "collective view of the Samoa Judiciary" in a letter to the Executive Director of the Law Reform Commission, dated 7 April.
Leaked to the Sunday Samoan publication, the letter was also copied to the Prime Minister, the Minister of Justice and Courts Administration, his CEO, and other senior legal officials.
It was signed by acting Chief Justice Vui Clarence Nelson and co-signed by all Justices of the Supreme Court and Judges of the District Court.
The letter also claimed to have the support of the Land and Titles Court, or LTC.
Plans to reshape the nation's judicial structure were introduced by Prime Minister Tuila'epa Sa'ilele Malielegaoi in Parliament last month.
Under the proposal, the LTC would be a parallel and independent judicial structure, including its own High Court and Court of Final Appeal and Review, removing the option to appeal its decisions to the Supreme Court.
The letter cautioned against the splitting of the nation's court system and warned about the need to safeguard the Constitution and the wisdom with which Samoa's ancestors wrote it.
"Any structure that separates the interpretation and protection of Constitutional rights between two Court systems is in our respectful view
flawed, unworkable and carries significant inherent risks," said the letter.
"This is a slippery slope and we are sure the Government does not want the Constitution to become the plaything of politicians," it warned.
The judges recommended the complete withdrawal of the "dangerously ill conceived" Constitution Amendment Bill 2020 and The Judicature Bill 2020 until their consequences could be considered more fully - including wide ranging consultations.
The Samoa Law Society also voiced concern over the amendments to the Supreme Law and called for country wide consultations.