In a career spanning four decades, Lord Ashcroft — born Michael Anthony Ashcroft — has assumed a variety of mantles. He was a callow accountant, an up-and-coming contract cleaning entrepreneur, a Thatcher-era corporate raider, Belize’s Ambassador to the United Nations, and treasurer of the Conservative Party.

Yet it is his latest incarnation that may raise eyebrows. Meet Baron Ashcroft of Chichester KCMG, ecological warrior.

This week, Lord Ashcroft will emerge as the backer of a campaign — or, in his words, “a programme of persuasion” — aimed at coaxing six eastern Caribbean countries to withdraw their support for whaling. The island nations — Antigua and Barbuda, Dominica, Grenada, St Kitts and Nevis, St Lucia and St Vincent and The Grenadines, which between them have a population of 560,000 — receive a total of $16 million (£8 million) a year in fisheries aid from Japan. In return, they have consistently voted with Japan and its principal ally Norway at the International Whaling Commission (IWC) to overturn the 1986 moratorium on commercial whaling.

With the next IWC convention due to be held in Anchorage, Alaska, next month, Lord Ashcroft has devised and funded a television advertising campaign — which will break in these six nations this week — to highlight a pro-whaling stance of which he believes the majority of their peoples are unaware and which has never been subjected to vigorous public debate.

But lest anyone run away with the idea that Atlantic Goose, the 150ft motor yacht on which he traverses the world’s oceans, could become the next Rainbow Warrior, he is keen to make one point clear.

“I do not profess to be a conservationist nor an environmentalist,” he says. “Other than the minor exception of aboriginal subsistence whaling in small countries, I believe there is no justification on either scientfic or commercial grounds for the killing of what I regard as some of the world’s most beautiful creatures.”

So how did he get involved? The roots of his engagement go back to Belize, the former British colony where he spent three years as a child and where he has commercial and charitable interests.

Just over a year ago, the Environmental Investigation Agency, the London-based pressure group to which he had previously provided support, approached him to use his influence within Belize to seek its continuing support against proposals for the resumption of whaling at the 2006 IWC meeting at St Kitts.

He is an avid whale-watcher: from the Bay of Cortez in Mexico, where grey whales breed, to the fishing grounds of the South Atlantic, where he has observed humpback whales from a matter of feet.

“Every month I’m on the water somewhere,” he says. “I’ve grown a close affinity, not just for whales, but for dolphins and porpoises. So it wasn’t difficult for me to approach the Belizean authorities with such a brief.” He discovered that Belize’s annual subscription to the IWC — £10,000 — had lapsed and came up with the cash. That backing yielded swift results when a crucial vote was won by the anti-whaling nations by a majority of one.

“The presence of Belize was critical,” he says. “Even though Japan and its supporters would have required a three-quarters majority to overturn the current ban, the fact that it was Belize’s vote that made the simple majority established the moral high ground.”

Ironically, his anti-whaling efforts correspond with those of a British Government for which he, now deputy chairman of the Conservative Party, evidently has little time. A British diplomatic campaign has led to six new nations joining the IWC over the past year, but Lord Ashcroft is unimpressed and claims to have been “disappointed” by the answers that he received from the Government in response to questions he tabled in the House of Lords last year on its attitude towards whaling.

Lord Ashcroft’s environmental stance might appear to sit neatly alongside a Conservative Party whose slogan for next month’s council elections is “Vote Blue, Go Green”. A little too neat? “This has been going on for longer than that campaign has,” he retorts. “And I’m not putting myself forward as an environmentalist. I just like whales.”

But he does appear far removed from stereotypical hunting, shooting and fishing Tory grandee of old. “The most I’ve ever done in my life is go on the occasional bird shoot,” he says, “but I didn’t really get any pleasure out of it, and I haven’t done it for 20 years.”

This week’s launch aside, Lord Ashcroft has plenty to keep him busy. Within the Conservative Party, his current focus is on opinion research and the oversight of marginal seats. In business, he still has stakes of between 20 per cent and 70 per cent in eight London-listed public companies, including Carlisle Group, his core support services vehicle. He plans to add to these by creating “another couple” of AIM-listed cash shells over the coming months. He also has a 42 per cent stake in Watford Football Club.

Perhaps paradoxically for a man not averse to the spotlight, most of his business interests are now in the private, rather than the public arena — notwithstanding the sale last year of his stake in British Car Auctions, previously his largest private business, for £200 million.

He turned 61 last month but advancing years have not diminished his appetite for a fight. So far, the millions he has donated to the Conservative Party have not been matched by electoral success. For now, the smaller sums he is putting behind the world’s largest marine mammals seem more certain of making their mark.

Curriculum Vitae

Name: Michael Anthony Ashcroft / Baron Ashcroft of Chichester KCMG
Born: March 4, 1946
Education: King Edward VI Grammar School, Norwich; Royal Grammar School, High Wycombe; Mid-Essex Technical College, Chelmsford
Career: Chairman, BB Holdings since 1987; varied business interests, with significant investments and participation in both public and private companies in the UK, US and Caribbean. Former chairman of Hawley Group Ltd, ADT Ltd and Cope Allman International plc. Director of Tyco International Ltd, 1984-2002
Family: Married with two sons and one daughter
Hobbies: Researching the Victoria Cross; entertaining friends; trying something new; messing about in boats

The leader questioned

If you could change one thing in the financial and commercial environment, what would it be? Petty red tape. Because it slows down the implementation of decisions

Who is, or was, your mentor? My father, Eric Ashcroft

Which is more important: what you know or who? What you know. Because you can always find out who can help you

Does money motivate you? Not in itself. But in business, money is a measurement of success

What was the most important event in your working life? I don’t yet know. I'm still working!

What gadget/piece of technology can you not do without? My mobile phones

How do you relax? Finishing The Times’s Killer Sudoko, which gets sent to me every day irrespective of where I am in the world

What does leadership mean to you? The ability to influence the outcome of events

Who do you most admire? In modern times, Winston Churchill

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive