I have an idea!

Yep, baited traps. My traps get baited with tomatoes in the summer.I get mice on mine but often see shrews dawdling around and the last month my pots on the floor have been upturned by mole hills. I get rats too ;(

Instead of putting pots on pots, could you put the plant in a "cage" inside something like a ?compost bag that a vole couldn't get a grip on to climb up to the chillies?

^^^ I've got my sweet peas sat inside a huge cardboard box that's 3/4 filled with plant pots.
It's worked so far.

We lost my sons gerbil once...I could hear him but every time I went in the room I couldn't decipher where the noise was coming from.

Eventually the worst thing happened - the smell! I found that he had climbed up the chimney wall and fallen into a very tall glass vase that was wedged in the corner. He couldn't climb out as the sides were too slippery.

Instead of putting pots on pots, could you put the plant in a "cage"  inside something  like a ?compost bag that a vole couldn't get a grip on to climb up to the chillies?

I’m surprised they can get in the pots anyway. Because none of them are shorter than MFB. I don’t have enough cage material/ compost bags for 40+ chillies. Embarrassingly I’ve got a of pots.