The eco-activist facing trial in India on terror charges has had to cancel the rest of his round-the-world trip because his budget has been blown on legal fees.

Andy Pag, 35, who is campaign against using fossil fuels by touring the world in a bus powered by chip fat, was arrested in January in the state of Rajasthan, in northern India, because he was carrying a satellite phone without permission.

The campaigner from Thornton Heath, who has dual Italian and British citizenship, spent a week in an Indian prison awaiting trial.

He said: “I’m keeping my spirits up, but I could face more prison time, and the legal expenses run to about 6,000 euros, a significant dent in the budget, which means I won’t be able to afford to finish the journey.

“It is disheartening as the journey was going so well, and I hadn’t used a drop of diesel in more than 16,500km since leaving London.”

He also fears his trial might be delayed indefinitely by police who say they need more time to put their case together. It has been adjourned five times so far because police are unable to put a charge sheet before the court.

Mr Pag is appealing for people to write to the Indian Minister of Home Affairs, the Indian High Commissioner in London and the Indian High Commissioner in Rome to put pressure on the investigating officer, Superintendent Tak of Ajmer Police, Rajasthan.

He said: “This is my last resort and I hope it will motivate the officer to complete his investigation. There is no legal time limit. It’s already been six weeks, and until they do I am trapped in India.”

Malcolm Wicks, Croydon North MP, said: “I’m concerned to hear this and I have urged the British High Commission to intervene.”

He has been charged under section 70 of the Information Technology Act, section 4/20 of the Telegraph Act and section 3/6 of the Wireless Act. All carry custodial sentences, the minimum of which is two years. He faces 10 years in prison if convicted on the terror charges.

To help email Mr P Chidambaram, The Indian Minister of Home Affairs on hm@nic.in, Mr Nalin Surie, the Indian High Commissioner in London on administra tion@hcilondon.in and Mr Arif Shahid Khan, the Indian Ambassador in Rome on gen.email@indianembassy.it.