In a report published this week, the ODPM Commons select committee claimed that more than 3,500 Gypsies and travellers have no legal place to stay.
This situation is unlikely to change without government intervention, it cautions.
The government should set up a Gypsy and traveller task force to identify potential sites and ensure nationwide vacancy co-ordination, the MPs add.
A capital grant should be provided to ensure that local authorities have the resources to pinpoint sites, the report recommends.
The committee argues that if more sites were available, the police would be able to move on illegal campers more quickly.
Responding to the suggestions, the ODPM said that a duty to provide sites has been tried before but has often failed to produce sufficient or appropriate provision. It pointed out that the current housing bill will require local authorities to carry out housing needs assessments and to develop suitable accommodation strategies.
The RTPI welcomed the MPs' call to use regional spatial strategies to identify sites for Gypsies. But president Mike Hayes said: "Often resistance to new facilities comes from local communities. If this is to be overcome, local authorities need resources to supply well-designed and well-maintained facilities."
Local Government Association chairman Sir Sandy Bruce-Lockhart said local authorities would need more funding to provide adequate sites and tougher powers to deal with illegal ones.
Gypsy and Traveller Sites can be viewed via www.PlanningResource.co.uk.