Ipswich council is facing a race against time to get the masterplan for the largest development in the town since the 1950s approved.

They are set to debate the masterplan for the 3,500-home northern fringe estate at next month’s full meeting of the borough – despite fears that some issues are not fully ironed out.

Council leader David Ellesmere told last night’s meeting of the Labour-dominated borough executive there could be no delay because an application to build 800 homes had been lodged by developers Mersea Homes and it was vital to have an interim Supplementary Planning Document (SPD) in place before it was discussed by the authority.

Mr Ellesmere said: “Frankly it would be better if we did not have this application hanging over us, but it is so we need to get on with this.”

Ipswich Conservative MP Ben Gummer was at the meeting to back up Conservative calls for a delay of a few weeks to make changes to the SPD, and he agreed it would be better if there had not yet been a planning application lodged.

He had warned there were serious issues that needed to be resolved in the document – the most pressing was the question of transport links to the thousands of new homes.

He said: “This is perfect for more high-quality cycle links with the town centre like there are in London or Bristol but there is no detail on that. And there are few details about how the roads will cope with more traffic.”

He also pointed out that designs showed a cricket pitch being proposed for the side of a hill, and an illustration suggested there would be two lakes, when in fact these would be grass areas designed to soak up occasional heavy rain.

Borough executive member for planning and economic development Carole Jones said the SPD would be an evolving document to provide guidance for development as plans were submitted.

She said: “We don’t know what the traffic is going to be like in five years so we cannot make firm decisions on everything like that now.”

The borough had looked at designs across the country before working with planners David Lock Associates to draw up the masterplan for what is now officially called the Ipswich Garden Suburb.

Mr Gummer had suggested it would be good to look at new developments in Cambridge. Ms Jones said they had seen award-winning developments in Cambridge but there were also some that had not worked well.

And her colleague Phil Smart warned the Cambridge situation was different because of inflated house prices in the city.

He said: “You can get much more out of developers if they can sell their houses for much higher prices – we need to be realistic about what we can achieve here.”

The executive decided the SPD should be fully debated by the full council on September 17. Chief executive Russell Williams said there were no other contentious items planned for that meeting – and expected the northern fringe would be able to dominate it.