A firm of developers is thought to be ready to spend up to £500,000 as part of a housing scheme – to accommodate a bridge for dormice.

A six-page document has been drawn up looking at how to cater for the rodent population, which has held up a major development in Crewkerne for three years.

Taylor Wimpey UK Ltd wants to build 525 homes on the so-called CLR site, which is on land east of the town, between the A30 to Yeovil and the A356 to Dorchester.

The development will include employment buildings, a primary school, community facilities and playing fields. It also involves changes to the landscape and infrastructure to include a link road and highway improvements.

In 2007, the developers were granted outline planning permission for the site but the presence of dormice means they must come up with ways to preserve their habitat before work can begin.

Included in the Crewkerne Dormouse Mitigation Strategy, created by Taylor Wimpey and wildlife specialist Ecology Solutions, are plans for a dormice bridge across a proposed link road. It is believed it will cost £500,000 and will be surrounded by two-metre high security fencing.

A district council spokesman said: "This is a good start. We are working with the applicant to make sure the mitigation measures are at a standard that we think Natural England will find acceptable when it comes to consideration.

"Discussions are going ahead and changes are being made so it's a real work in progress."

David Matthews, land and planning officer at Taylor Wimpey said the firm has been in meetings with Natural England, the district council and Somerset County Council.

He said: "We've worked very hard for the past two years and I would say we are almost there with this."

Crewkerne town councillor Mike Best said: "This has been going on for many years and if an agreement can be reached on a positive strategy, then it is good news at last.

"The dormouse situation is a big issue. They make things more tricky.

"If it had been badgers or foxes it would have been a lot easier because you can build a tunnel and they can go underground."

Beth Jerrett, of the Somerset Wildlife Trust, said: "Dormice are one of the rarest mammals across Europe so they have a huge degree of protection.

"They exist only in small groups per hectare of land, so it's critical they can find each other. If a development threatens to divide them, then provision must be made."