The plan would see the marina's capacity doubled

On Tuesday, Gwynedd council's management board commissioned a study on the possible effects of the scheme on the Welsh language.

This means in effect that the planning application has been deferred for at least another three months.

Some members of the council fear the plans could lead to an influx of non-Welsh speakers.

There are currently 400 moorings at the marina, but the plans suggest that should be increased to 700.

It is an opportunity to look at the wider implications of the marina project Councillor Dafydd Iwan

Last month, a decision on the scheme was deferred after councillors complained they had not been given enough time to read relevant documents.

Some had received the papers only the day before the meeting.

The decision to commission the study was made at Tuesday's meeting in Caernarfon.

Proposing the move, councillor Dafydd Iwan - who is also president of Plaid Cymru - said "a linguistic assessment should be taken as a serious option".

"Rare bat colonies, squirrels and shellfish would be given an environmental assessment within the planning process," he said.

Dafydd Iwan proposed the study on the scheme's impact

"It is only right and proper the language should be given similar treatment.

"It is an opportunity to look at the wider implications of the marina project."

Opposing the study, another councillor, Eddie Dogan, said: "The language issues shouldn't be part of the planning process."

Those who favour the scheme, including the town's Plaid Cymru councillors, said the development would bring economic benefits and a failure to make improvements would mean the investment goes elsewhere.

But other Plaid councillors feared such an increase would lead to a large influx of non-Welsh speakers which, in the long-term, could damage a traditional Welsh language heartland.