New House of Commons summary of the law regarding unauthorised sites. The full report can be read here (pdf)

Gypsies and Travellers: camp sites and trespass – Commons Library Standard Note

• This note describes some law relating to Gypsies (Roma) and Travellers. It mainly covers issues relating to camp sites and trespass, including the Anti-Social Behaviour Act 2003. The issues arising when Travellers buy land and undertake unauthorised development upon it are covered in another note – Gypsies and Travellers: unauthorised development.

• The Criminal Justice and Public Order Act 1994 introduced strict provisions to allow local authorities or the police to move on trespassers. Many councils have been reluctant to use the 1994 Act provisions, partly because Government guidance required full attention to be paid to the welfare needs of all the trespassers. It is probably not compliant with the European Convention on Human Rights to evict trespassers who have nowhere to go.

• The Labour Government pressured councils to make adequate provision for Gypsies, partly through the Housing Act 2004 and partly through Regional Spatial Strategies and Local Development Frameworks.

• A letter to councils from Secretary of State Eric Pickles of 27 May 2010 states that “decisions on housing supply (including the provision of travellers sites) will rest with Local Planning Authorities without the framework of regional numbers and plans.”

• The May 2010 spending cuts for the Homes and Communities Agency have ended the Gypsy and Traveller Programme grants for new sites, thus saving £30m in 2010/11.

• On 29 August 2010 DCLG announced stronger tenancy rights on authorised sites; new incentives to build authorised sites; the abolition of Whitehall guidance; stronger powers to tackle unauthorised development.

• On 13 April 2011 the Government published a consultation on a new circular relating to planning for Gypsy sites.

• In January 2012, the Government announced funding for camp sites.