The short time period for public submissions on the new counter-terrorism law "is really problematic", says Amnesty NZ.
However, Justice Minister Andrew Little pushed back on criticism, saying he would not sit on his hands while there was "an imminent threat".
Last month, the Government announced a bill to "prevent terrorism and de-radicalise New Zealanders coming back from overseas" as tensions rise in Syria.
It comes after US troops were pulled from northern Syria and Turkish forces moved in, increasing the possibility of foreign ISIS fighters such as Kiwi Jihadi Mark Taylor returning home.
The Justice Minister's aim to get the proposed law into force by Christmas would not allow for the "crucial safeguard" of a timely process, Amnesty executive director Meg de Ronde told 1 NEWS last month.
It was announced on Tuesday that the public has until Sunday to make submissions on the proposed law change.
"Minister Little said he wanted to push it through by the end of the year - that alone was concerning to us," Ms de Ronde said.
She said the submission time was not enough "for constructive engagement with civil society".
"It’s really outrageous and provides virtually no time for response. This is a really concerning approach to justice."
"We need to enable input from people who are international experts, with people who focus on issues of liberty and freedom and participation from everyday people who may be impacted. That’s not what’s happening here."
Amnesty created a petition asking Mr Little to slow down the submission process and has received 1672 signatures.
"People expected that this would be a free, fair, transparent and accessible Government. This process doesn’t seem to reflect that," Ms de Ronde said.
Mr Little said the timing of the law was about putting the safety of New Zealanders first and, with the chance of overseas terrorist fighters returning in the short term, the importance was "higher than ever before".
"The situation in Syria is changing rapidly," he said. "There are New Zealand passport holders there who are likely to seek to come back to New Zealand at any time and we need to be prepared.
"This is an imminent threat we are dealing with, and I’m not prepared to sit on my hands when it comes to matters of national security.
"I have already signalled my intention to have the bill passed before the end of the year, which naturally requires a truncated select committee period. This is an interim measure to deal with a real and growing risk while the review of the Terrorist Suppression Act is under way, which is not due for completion until next year."