A liaison officer at the pro democracy office in Tonga, Siosiua Pohiva, says it has instructed its lawyer to clarify what the limits are to extending emergency powers in the kingdom.
The Minister of Police has advised that the emergency powers, which came into force after the November riots last year, be extended for a sixth time.
This time, Tongatapu is the only island covered by the extension.
The minister also said that public gatherings of five people or more can now go ahead, even if they are political meetings, but at the discretion of police.
Mr Pohiva says the restrictions affect the movement's work.
"We are saddened by the continuous restrictions because we think that currently there is no more crisis, and no more threats to the country. We think we should be allowed to meet independently and to go ahead with our normal agendas and work plans at this point in time."
Siosiua Pohiva says it will abide by the requirements and tell police about any gatherings it plans to hold.
