The Hague–"We need to finalise our preparations before we can put the project into operation," Petro Hermans, a project officer for the southeastern city of Maastricht, told AFP.
"We are studying the legal feasibility of the project," he said, adding the date of 1 January "was not practicable".
The mayors of Maastricht and seven other municipalities in the southern Limburg province announced last May that about 30 coffee shops within their borders would become private members’ clubs from this year.
The daily limit would be reduced from five to three grammes of cannabis per client, while patrons would require membership cards and a Dutch debit card to pay with — effectively cutting off tourists.
The Limburg move is backed by the national government, and is one of several pilot projects whose results will be incorporated in a new policy that will aim to reduce the "nuisance" caused by drug tourism.
About four million foreigners, mainly Belgian, French and German, visit Limburg every year to purchase cannabis. The Dutch government decriminalised the consumption and possession of under five grammes of cannabis in 1976.
There are some 700 licensed coffee shops throughout the country, but cannabis cultivation remains illegal.
Hermans said a report of university experts on the feasibility of the pilot project would be delivered to the mayors of the eight municipalities by mid-January.
"We will then decide how to proceed," he said, stressing that the mayors were "eager" to get the ball rolling.