THE Prime Minister has cited the delay in dredging Falmouth harbour as an example of how projects that could boost the economy are put in the "too difficult" box.
But in a joint statement, the Falmouth Bay and Harbour Action Group, Falmouth Friends of the Earth, the Marine Conservation Society and CPRE Cornwall have criticised his comments and said he had a "warped view" of the licensing procedure.
The £20 million scheme is part of a wider masterplan for the port, but the Marine Management Organisation (MMO), which has to give permission for the dredge, has so far blocked the scheme because of environmental fears.
It is currently the subject of a trial dredge to try and provide evidence that a full dredge to create a deep-water channel will not have an undue effect on the seabed, in particular on maerl beds.
That will conclude next year, when the MMO will make a final decision.
David Cameron told the Liaison Committee of MPs: "Often the problem can be solved, but it's put into the too difficult box, like in the case of dredging Falmouth harbour, where we raise these things at cabinet level in order to try and get departments to bring up things that they are blocking and explain why they are blocking them and see if we can find a way through it."
The statement from opponents said: "We are very concerned with the Prime Minister's recent comments. He exhibits a worrying view of the licensing procedure in which approval is the only correct and proper outcome.
"If consent for a project is not forthcoming, his comments imply that this can only be because environmental agencies are not doing their jobs properly.
"If Sainsbury's wanted to build a supermarket on the site of Stonehenge, everyone would grasp instinctively that this should never be allowed.
"People who understand and respect the marine environment see the proposed dredging of the Fal estuary and the associated plan to dump of one million tonnes of dredge-spoil in Falmouth Bay in the same way.
"The Fal's maerl beds (coralline seaweed), which are threatened by the dredging, are at least as old as Stonehenge and every bit as special as they are unique in England.
"The other worrying aspect of the PM's statement is that it puts inappropriate political pressure on the Marine Management Organisation.
"The MMO is legally obliged to decide the matter on a strictly precautionary and scientific basis. The PM should listen, have a view by all means, but let the MMO do its job, and come to an independent decision based on the likely impacts, without political interference.
"The PM's statement is yet further evidence that his pledge to lead the 'greenest government ever' was deeply misleading.
"What this government clearly wants is development at any cost."