But after 45 years living in Hong Kong he will be speaking out no longer - at least not in the territory in which he has become an institution. "There comes a time," he says, "when you stand down and step out." Within weeks of China's five-star flag being raised over Hong Kong, Jimmy McGregor will be gone. He will have left the Governor's Executive Council, or cabinet, bade farewell to an enormous circle of friends and boarded a plane with his Chinese wife for either Britain or Canada.
Mr McGregor's departure gives meaning to the cliche about the end of an era. For the better part of five decades he has been at or near the centre of government in the colony. The Edinburgh-born 72-year-old has become so closely identified with the business and politics of Hong Kong that it is hard to imagine them without him.
Like one of the characters in a Paul Scott novel about post-imperial India, it seemed that Jimmy McGregor would be among those staying on. "I never had a feeling of specific loyalty to Britain," he says. "I had a feeling of loyalty to this place." And he might have remained if he thought there would be a place for him in the new order, "but my differences of view and my track record are such that I would simply become a mere cantankerous complainant." He cannot envisage the new regime creating a system in which dissident views would be readily appreciated, adding, "I know of others more capable of making the transition."
When he arrived in Hong Kong back in 1951 as an RAF armament sergeant, Mr McGregor quickly realised he wanted to stay. The colony was dirt poor in those days and overwhelmed by one and a half million refugees pouring over the border from China. Shelter had to be provided, jobs found, the children educated and law and order maintained. He transferred from the RAF to the Hong Kong civil service and was thrown into the deep end as a trade officer, creating the conditions to open up the colony for business.
By the time Mr McGregor left he was the acting head of his department and in charge of customs. He was lucky to be alive, however, having been singled out as a target by the Communist rioters who rampaged through the streets in 1967 as China's Cultural Revolution spilled over into the colony.
Mr McGregor was pushed to the front line in the government's counter- offensive. He even organised a public fund to counter the Communists' Anti-Imperialist Struggle Fund. A bomb was sent to his home and he was deluged with hate mail, attacks in the Communist-leaning press and death threats. He sued the main left-wing paper for libel and was about to be awarded substantial damages when word reached him that whatever he inflicted on the paper's editor would be repaid many times over by the Reuters correspondent, Anthony Gray, who was held by Red Guards in Peking.
Mr McGregor backed off, and later became friendly with the editor he had sued, a relationship which paid off when he left the civil service in 1975. The editor helped him establish the ties in China he needed in his new job, running the Hong Kong General Chamber of Commerce, the colony's main business organisation. He chuckles at the accusations of his enemies in the chamber who called him "anti- Chinese", always having believed that Hong Kong's economic future was "irreversibly tied up with China".
After Mr McGregor retired from the chamber he was elected by its membership to represent them on Hong Kong's Legislative Council, where he emerged as one of the most effective independent voices. He was popular among the small businessmen who made up the majority of the chamber's members, and among the public at large, despite being one of the few non-Chinese on the council. But the big businessmen on the committee of the Chamber of Commerce saw him as a dangerous radical, unnecessarily rocking the boat with China.
"I broke the ranks," he says. "I understand the individual businessman's point of view. They don't want to stand out and take individual responsibility for criticising China, but business is represented by major organisations which China does listen to, and they should tell China when it's doing something in the wrong way."
Mr McGregor retained the loyalty of the smaller fish in the business world, and won a second term in the legislature, but the big guns were being rolled out against him. He decided not to run again in 1995, but accepted an offer from the Governor, Chris Patten, to join his cabinet, "on condition that I was not going to be anyone's rubber stamp".
The Chinese government insists that it wants non-Chinese to stay in Hong Kong and play a role, but Mr McGregor does not believe this will extend to politics. He swears blind that Britain largely kept out of the colony's affairs - a "hands-off" policy which he believes was responsible for Hong Kong's success. His main fear now is that China will not behave in the same way, and that the autonomy it promised Hong Kong will never materialise.
So, "all things considered, it's probably time to shut up," says Jimmy McGregor, adding wistfully, "It's not so easy."