Controversial plans for 400 homes in Newmarket could be affected by this week’s Government announcement that RAF Mildenhall will be sold with a view to build 4,000 homes.

In the days since the Ministry of Defence announcement some people have linked the two issues, with the planning appeal decision on Hatchfield Farm delayed until at least the end of this month despite being due last year.

The argument potential housing on RAF Mildenhall, or the sudden availability of housing as thousands of US Air Force personnel leave rental properties, should be taken into account was originally brought up by the horseracing industry during their fight against Hatchfield Farm at last year’s planning appeal.

The argument was dismissed at the time by Forest Heath District Council representatives as an “implausible” planning policy. It was argued that there was a housing need in Newmarket, regardless of the situation in Mildenhall.

A spokesman for Forest Heath District Council, the planning authority, said: “The RAF Mildenhall site will be occupied until 2022 and there will be land condition issues to be investigated and resolved. We are not able to guarantee when houses could be built there.

“There is also the need for a development to be sustainable, with the right balance of housing, employment and infrastructure...none of which has been discussed with us by the MoD at this stage.

“The local plan...is about ensuring we are meeting the needs of our existing and growing population by having land designated for housing, employment and other uses [up until 2031].

“Should the site become available early, the local plan will be reviewed early and a masterplan will be prepared for the site to ensure development includes the necessary services and infrastructure to ensure a sustainable development.

“The decision of our members to approve the Hatchfield Farm application, has been heard at appeal and we now await the Secretary of State’s decision.”

Newmarket Town councillor Warwick Hirst, who supports Lord Derby’s plans for homes at Hatchfield Farm, said that the scale and history of military use at RAF Mildenhall, which dates back to 1934, would mean that many parts of the site would need decontaminating.

“I am no expert,” he said. “But with military use for that many years you would have thought it is going to need an extensive clean up. Whatever is planned for RAF Mildenhall, it might not be fit for housing for at least 10 years.”

The planning appeal, which took place in April 2015 over the course of three weeks, was brought about after Forest Heath’s decision to permit the 400 homes.

The horseracing industry, represented by the Newmarket Horsemen’s Group, were opposed to the development on the grounds that it would damage the future of industry.

A key crux of their arguments was that it was presumptive of the long awaited local plan for the district, which will allocate the district’s 6,800 home 15-year housing need.

William Gittus, chairman of the horsemen’s group, said: “Whether it [the RAF Mildenhall announcement] affects the decision or not is up to the Secretary of State [for Communities and Local Government].

“If nothing else this shows why planning decisions need to be looked at through the local plan process with all of the issues assessed – rather than as the result of an ad hoc decision placing houses on unallocated land [Hatchfield Farm].

“It is clear from the announcement that the potential housing on RAF Mildenhall should form a part of the local plan process. It has a significant impact on what goes on in Newmarket in the future and in the rest of the district.”