Housing targets proposed for Hertfordshire are “completely unrealistic” according to planning chiefs.

Local authorities across the county have unanimously agreed to protest against housing figures proposed by the East of England Regional Assembly (EERA), which would mean thousands of new homes for Hertfordshire.

The Government has called for all regions to increase targets for housing over the next 23 years, meaning Hertsmere could face a hike in new developments.

The borough must create at least 5,000 extra homes by 2021. But EERA has now extended the date to 2031, and has increased the original target by about 60 per cent.

Richard Grove, Hertsmere Borough Council’s head of planning, said: “These figures are scary increases on the numbers we already have. This, along with the concerns of infrastructure and the lack of funding, are some of the reasons why we are fully supporting the move to question the numbers.

“In Hertsmere these figures will have major issues for the Green Belt. We have to look at the plan for 2021 rather than looking at further growth.”

EERA has only until the end of the year to report back to the Government with changes to the original plan, sparking fears from county and borough councils that not enough time is available for a thorough public consultation.

Derrick Ashley, executive member for planning at Hertfordshire County Council, said independent consultants employed by the authority have major concerns about the figures. He said: “While we agree there is a need for more affordable housing, independent consultants support the fact the increased scales of development being looked at are completely unrealistic.

“This is why our advice to EERA is to further examine the impacts of the figures before trying to find a way to shoehorn more homes into one of the most densely populated counties in the country.”

Mr Ashley continued: “Aside from our concerns about the level of growth and lack of infrastructure, we continue to question the ridiculously tight deadline the Government has imposed on EERA to deliver the 2031 plan. The timetable doesn’t give us time to understand the long-term impacts of issues such as the credit crunch.”

EERA will now look at the information and advice provided by strategic planning authorities and developers in the region, and will hold a public consultation on its plans in the spring.

A schedule of proposals from developers and a public information pack on the East of England Plan — Review to 2031 is available at eera.gov.uk