Insurance for ACCA Spare time practising certificate

I would like to apply for an ACCA spare-time practising certificate in order to be able to sign off some clubs and associations independent examinations.

I am an FCCA and held a practising certificate for a short while in 2005 and 2006 which I decided not to renew.

The fee income will be 0, so will be entitled to the reduced £83 fee for fee income of less than £5k.

I'm not in practice (and don't intend to be) - this will be purely to ensure I follow ACCA's recommendations.

So the big stumbling block is insurance cover.  Does anyone have any recommendations  ? Is there any insurance cover which is relevant to this situation and doesn't charge an arm and a leg.

Thanks.