The 60-year-old is an outspoken critic of hunting and has been subjected to intimidatory tactics like having dead birds tied to his fence and excrement sent to him in the post.

In a six minute clip, posted to his social media accounts, Mr Packham, who sits on the board of a number of conservation charities, said: “So on Thursday night, Friday morning, 12.30am, two hoodied and masked men drove a vehicle right up to my gate and set it on fire.

“They were fully aware of the CCTV that was in place – they took great pains to hide themselves. The car exploded and was rapidly and efficiently dealt with by Hampshire Fire and Rescue and the police were in attendance.

“As ever, they did a fantastic job, but not before it had caused extensive damage to my property.

“This leaves me with some questions. Firstly, who were these two men?”

He mentioned the charities he sits on the board of – The RSPB, The Wildlife Trust, Butterfly Conservation and Bat Conservation Trust – before asking: “Were they members of the hunt, perhaps?”