This is a stab in the dark, but I had a similar problem with an Astra once.
You could also put your foot on the brake, take the keys out of the ignition and the engine would continue running. It only stopped when I released the brake.
The answer to the problem?
A brake light bulb had blown a week ...

Hi all, newbie here.

Had my Bongo about a month and have so far successfully changed the oil, oil filter and the fuel pump seals, the last being a pig of a job as you can't see what you're doing.

The issue I have got is that in addition to the oil and fuel leaks, the Bongo seems to be leaking ...