Illegal Travellers' sites almost doubled in Sussex last year as plans to create official camps were attacked by angry residents.

The latest figures from the Office of the Deputy Prime Minister show the number of unauthorised encampments across Sussex rose from 64 to 118 between January and July.

While some Sussex councils have reduced the number of illegally-parked caravans, others have seen large rises. Travellers moved on by one council appear to be pitching up in neighbouring authorities.

The single biggest rise was in Brighton and Hove, where there were no illegal sites at the beginning of 2005. By the summer there were 48 unauthorised pitches in the city.

The city council spent £142,470 dealing with travellers last year.

A spokeswoman for the council said: "The rise between January and July is normal. Travellers move around more during the summer - it's the same every year."

The areas where illegal sites increased were all in East Sussex. Numbers rose from none to 26 in Mid Sussex, two to 14 in Lewes, 11 to 14 in Wealdon and none to four in Hastings.

Numbers fell from four to three in Chichester, 19 to seven in Crawley, 24 to two in Horsham and four to none in Worthing.

The figures come as many Sussex authorities are facing local resentment towards travellers.

In Shoreham last week, travellers were served a notice to leave Mill Hill's car park by Sunday.

In Crawley, officials overturned approval for two more traveller sites after more than 1,000 people turned up to protest against the decision.

The council spends £300,000 per year dealing with travellers. In a separate battle, travellers have gone to the High Court to fight their eviction.

A spokeswoman for Crawley Borough Council said: "We are trying to balance the needs of travellers with the views of the settled community but the town's circumstances make that difficult. It is very densely populated and has the highest number of illegal incursions in West Sussex."

A spokeswoman for Friends, Families and Travellers, based in Brighton, said: "At the last survey count, 20 per cent of travellers lacked a site.

"There is a huge national shortage, reflected in Sussex. I think it's very foolish Crawley have abandoned those two sites. They're under a legal duty to provide them."

East Sussex has four permanent sites in Hailsham, Polegate, Maresfield and Robertsbridge and two transit sites at Lewes and Brighton. The last permanent site was set up in 1987. West Sussex has 11 sites in Lancing, Arundel, Henfield and two in Chichester, Billingshurst, Burgess Hill and Haywards Heath. The last permanent site was set up in 1980.