Hazel Blears' cheque to HMRC

We are told that Hazel Blears has sent a cheque to HMRC for the amount of CGT she might/should have paid. However if there was no CGT bill what is that cheque being paid against? Is it in fact going "on account" to be offset against future tax liabilities?

Hazel Blears needs to make it clear whether she has agreed a CGT liability with HMRC and that her cheque settled this liability or if her cheque is sitting in her tax account to be offset against future tax liabilities (less the interest accruing on her "overpayment".

If the cheque was in settlement of an agreed CGT liability, what happened to the interest and penalties that HMRC would normally demand on late notification and payment of a CGT liability?

This story is not as dead and buried as Hazel Blears and the BBC might hope.