Frustrated communities waiting to see the full impact Sizewell C could have on their lives will have to wait until next year for the details to be revealed.

Campaigners fear they will not have enough time to press for major changes if the timetable for seeking permission for the twin-reactor nuclear power station on the Suffolk coast speeds up.

Officials at EDF Energy had indicated the second stage of the consultation might be held this autumn, but now say it will be early in 2015 – though as yet no dates are available.

The consultation is likely to give the firm proposals on major issues such as whether it is intended to build a bypass for Marlesford, Farnham, Stratford St Andrew and Little Glemham, or a relief road for Middleton and Theberton, and details of where the accommodation campus and park and ride sites will be.

Although there will still be a third round of consultation, the final phase is expected to be a detailed technical exercise aimed at councils and other major organisations.

Leiston-cum-Sizewell town councillor Colin Ginger said: “It will now be more than a 12 month gap between the first consultation and the second one.

“It is more than frustrating. To be truthful, I think this consultation will be EDF telling us what they are going to do – the final plans rather than options. I think people will be shocked at what they hear and the later it takes place the fear is there will be less time to canvass against it.”

The Four Villages Bypass campaign has already expressed frustration at the lack of progress on transport proposals because of the time involved in the traffic analysis.

Mr Ginger said the site for the accommodation campus for 3,000 workers was also a contentious issue.

He feared that if the 40-acre site south of Leiston was chosen it would mean huge upheaval and loss of access to recreation in the area.

He said: “I think the campus should be at Ipswich or Lowestoft – those big towns and could absorb 3,000 extra people.”

Tom McGarry, EDF Energy’s head of communications for Sizewell C, said work on a wide range of issues as part of the preparation for the second consultation was still continuing, and there would be plenty of time and opportunities for people to have their say.

He said: “We do understand that local communities in Suffolk want to see more detail on our plans for the project. This will be a key part of stage two of our consultation.

“However, before we launch stage two consultation for Sizewell C we need to know we have everything in place to enable Hinkley Point C to go ahead.

“The final investment decision on Hinkley Point C is expected around the end of the year and therefore we expect to launch stage two for Sizewell C in 2015.”