No
Provided that the van is not damaged, otherwise you could be liable.[1]
If the bailiff refused to move his van blocking an access road on private land, then you may have a defence if you can show that you had a lawful excuse.[2]
If a bailiffs van causing an obstruction is moved using a forklift, then it is a defence if the obstruction was causing a loss to a business needing immediate access to land or buildings.
It is the practice of bailiffs to call the police on 999 when his van is lifted off the ground using a forklift, or moved off private land and set down on a highway.
If the van is blocking a driveway, and preventing you from leaving, then you should first, all the police. If they do not attend, then you can get help and move the van by lifting the rear wheels off the ground and moving it sideways to clear the drive.
Only lift a vehicle using a forklift by the rear wheels only. If you lift it sideways (broadside), the weight of the engine will cause the van to fall off the forks. You cannot lift the van by the front wheels because the handbrake might be engaged which locks the rear wheels.
When the rear of the van is on the forks, only move the van rearwards because the forklift rear wheels are the steerable wheels. Then tow the van rearward out from the obstruction.
[1] Section 1 of the Criminal Damage Act 1971
[2] Section 5 of the Criminal Damage Act 1971
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