Pension erosion

I have a small pension fund of 25k, which is now not being contributed to and just sitting waiting for a time when I can access it, presumably only on retirement from age 50 to 65?

It is subject to charges, probably around the going rate of 1.5-2% and government levies. With very little growth or returns expected for the forseeable future and 20-30 years max to retirement is it possible that a significant amount of it will be gone in charges and levies by the time I can access it? Or have I missed something?

Is there any way to prevent this, or remove it from the pension company into a static fund so that I can at least remove the charges if not the government levy?

There's no pension company offering its services for free, so there will inevitably be charges and there's nothing anyone can do pre-retirement about the Government levy.

Your figure of 1.5% - 2% per year plus Government levies seems high. It might be possible to transfer the fund to something with lower ongoing charges.