An "important milestone" in the construction of the Watford Health Campus was passed last night, as a new road linking the site to the M1 was granted planning permission.

The scheme will see the road cut through the Oxhey Park playing fields, across Wiggenhall Road, and through the Cardiff Road Industrial Estate, which is due to be redeveloped.

Watford Borough Council’s development control committee voted to approve the road, which is estimated to cost £18.5million, last night.

Phil Woods, speaking for the project, said: "Today is an important mile stone in delivering the health campus. This will ease congestion and provide access to thousands of patients and visitors.

"The road will provide access to new residents and workers in the health campus, which has been a long-term regeneration priority for Watford."

Outline planning permission was granted in 2010 for a masterplan for a large scale redevelopment of the hospital site, Cardiff Road industrial estate and former Carriage Sheds site as part of the health campus. The road was identified as "integral" to the plan.

Council officers said some of the buildings on the estate contain asbestos, and invasive species such as Japanese Knotweed. There may also be a risk of "unexploded ordnance".

Councillor Nigel Bell said: "For years I have been calling for the regeneration of the Cardiff Road Industrial Estate and it’s an important development for the hospital’s facilities.

"One hopes it will ease congestion on Vicarage Road and the surrounding roads in Watford. The loss of green space in Oxhey Park is sad and drainage and flooding is a big worry."

Letters were sent out to 115 properties in the area and eight replies were received, raising concerns about the loss of playing fields and damage to the river.

The road will plough through a Gaelic football pitch and single football pitch, as well as the changing rooms in the Irish Centre building, a hard court used for tennis and basketball.

One complainant said the road was being built to "serve a commercial development which may not be economically successful" and would result in the loss of Irish Centre.

A lake will also have to be created to negate the effects of building the road in a flood plain.

Councillor George Derbyshire said: "This is an absolutely key moment in the health campus development, which could not go ahead without additional access.

"I am thrilled to see this is now before us, this is probably the largest piece of public investment that has been in Watford for many years.

"People will be able to see there is work going on and they will be able to benefit from a new hospital and a significant number of affordable homes."

West Hertfordshire Hospitals NHS Trust is providing £7million for the road, and the Hertfordshire Local Enterprise Partnership will contribute £6million.

Councillor Mark Watkin added: "I absolutely support this scheme, is it critical that it goes ahead. This will open up the Colne Valley, allowing it to become an open space for the borough."