The House of Lords' decision in the case of Regina v. Commissioners of Inland Revenue ex parte Wilkinson indicated that HMRC's power to grant concessions was narrower than was previously supposed. In light of this, HMRC is reviewing all its published concessions and to date have concluded that the practice of "equitable liability" does not fall within the discretionary power of HMRC and will therefore be withdrawn from 1 April 2010.
In 1995, the Inland Revenue published a Tax Bulletin article 'Excessive assessments: equitable liability' (TB18). The article explained the circumstances in which information received after the statutory deadlines had passed might be accepted as evidence that finalised tax liabilities were too high and a decision taken not to pursue recovery of the full amount assessed. This concession was originally introduced to protect other creditors when the Inland Revenue's claims in insolvency cases took precedence over the claims of other creditors.
Full details of the withdrawal of the concession are available here