The after-hours GP clinic was originally designed to take pressure off the emergency department and overcome a lack of affordable, accessible GP treatment in the northern suburbs.

Northern Health acting chief executive Robynne Cooke said the increasing number of after-hours GP clinics in the area meant there was less demand for the Northern Health after-hours GP clinic.

Northern Division of General Practice operations manager Annette Knopf said the closure could mean limited access to services such as blood tests and X-rays in the short term.

"In the community they are less available so that's an issue not yet resolved," she said.

Ms Knopf said access to services such as pathology and X-rays would be assessed by a Medicare Locals,

the umbrella organisations which co-ordinate primary health care for a region.

Ms Cooke said the decision to close the after-hours clinic was made as part of the planning works for the redevelopment of the emergency department. The Northern Hospital emergency department is the busiest in Victoria, treating about 70,000 patients a year.

The redevelopment will add an extra 21 treatment spaces to the emergency department and seven cots to the Special Care Nursery.

Mill Park Super Clinic manager Nadia Siciliano said an overflow of patients were often sent from the Northern Hospital and the clinic could cope with extra demand as a result of the closure.

The federal government has also boosted short-term funding to support the Willandra Clinic in Epping to operate after hours until the end of June 2012.

The funding announcement was part of the $260 million federal investment in after hours care.