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He is hardly a household name, but the departure of Johan Eliasch is a significant blow to the Conservative Party.

Mr Eliasch, 45, is a talented sportsman and sportswear tycoon, a film producer, committed environmentalist and a longstanding Conservative. He gave the Tories a £2.6 million loan when it was in financial difficulties and, as deputy treasurer, played his part in restoring the coffers to a semblance of order.

As an adviser to William Hague, the Shadow Foreign Secretary, he was also influential in the development of foreign policy and the emergence of green Conservatism.

Last year Mr Eliasch, an Anglo-Swede, worked with the freethinking Labour MP Frank Field to establish Cool Earth, a charity that is dedicated to fighting global warming by buying up and protecting the equatorial rainforest.

One of the messages of support on the charity website is from David Cam-eron. But politicians’ words have never been enough for Mr Eliasch. Writing at the time of the setting up of Cool Earth, he said: “Not a day goes past without political statements on emission targets and Kyoto protocols. Every MP seems sure that global warming is the number one priority on their ‘to-do’ list. Unfortunately, a ‘to-do’ list won’t avert a global crisis.

“Like so many people, I despair of debate ever leading to effective action. This prompted me to leapfrog a debate with action.”

That leap was to buy 400,000 acres of land – an area larger than Greater London – in the Amazon rainforest, on which he has banned logging. The move led to accusations of “green colonialism” when it transpired that a thousand people had lost their jobs, but Mr Eliasch was unrepentant. He says that many of those jobs have been replaced, sometimes by the employment of security staff to prevent illegal logging. In any case, he says, the preservation of the forest is paramount.

“The Amazon is the lung of the world,” he said. “It provides 20 per cent of the world’s oxygen and 30 per cent of the fresh water.”

Mr Eliasch has subsequently donated £20 million to environmental projects and causes, putting him in 10th place on the Sunday Times Giving Index 2007. His personal fortune is assessed by the newspaper’s Rich List at £360 million.

Mr Eliasch, who is married with two children, was born in Sweden in February 1962. He is a scratch golfer who has played in qualifying rounds for The Open championship, a skier who has competed at international level and a trophy-winning curler.

His grandfather was a wealthy industrialist, but Mr Eliasch has made his own way and his own fortune in business, principally by buying and turning around failing companies.

Since 1995 he has been chief executive of Head, the Austrian sportswear firm, which was losing £36 million per year when he acquired it but is now a successful worldwide brand.

With his fortune secure, Mr Eliasch turned his attention increasingly to political concerns. In addition to his active support for the Conservative Party, he serves on numerous advisory boards and charities including the Shimon Peres Peace Foundation, Brasilinvest and Resources for Autism.

A British citizen, he counts the Duke of York as a friend and is an adviser to Iain Duncan Smith’s Centre for Social Justice and president of the think-tank Global Strategy Forum.

He has explained how his passion for fighting climate change stemmed from a personal realisation of how it was changing the world he knew.

Mr Eliasch once explained that his happiest times were the four months of winter when he could ski to school in Stockholm.

He wrote: “I’d wake up, struggle with clumsy bindings and set off on a journey that should take 10 minutes but I’d stretch to half an hour. That was in the 1960s when snow was such a familiar part of the long Swedish winter it wasn’t even remarked upon. Today, Stockholm’s children would be lucky to see a week of snowy weather.”

The Tories have pledged to match Gordon Brown’s spending limits for the next four years.

Writing in today’s Times, George Osborne, the Shadow Chancellor, claims that the move will neutralise one of the Prime Minister’s main attacks against the party.

“The result of adopting these spending totals is that under a Conservative government there will be real increases in spending on public services, year after year. The charge from our opponents that we will cut services becomes transparently false,” he writes.

Mr Osborne’s pledge commits the Tories to raising government spending by 2 per cent a year from £616 billion next year to £674 billion in the year 2010-11.

He also repeats the Tory pledge to lower spending as a proportion of national income in order to pay for sustainable tax cuts.

Conservative tax cuts will be paid for by tax rises, many targeted at reducing pollution, Mr Osborne indicates.

He commits the Tories to a “long-term sustainable plan to reduce the tax burden on families and on businesses”.

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