The client has brought in a county court summons issued by the collector of taxes claiming a large sum of tax b ased on assessments which were not appealed.

The client says that he does not owe this tax.

His former accountant forgot to lodge the appeals and his present accountant has been trying to agree accounts with the inspector of taxes.However, the collector is refusing to stay the action, on the basis that his case can be proved conclusively by certificates of tax due under s 70 of the Taxes Management Act 1970, and he intends to proceed to judgment.

He has said that any defence filed will be subject to an immediate application to strike out as an abuse of process.

The client takes little comfort from CCR ord 42 r 10, which is readily available, providing for adjustment after judgment since he maintains that any judgment against him will cause him economic disaster.

At the very least, he wants a stay of proceedings.The textbook answer is that the client should seek a judicial review of the decision to press on with the action while there is a bone fide issue as to the amount due.

Public bodies which do not act reasonably in reaching decisions are liable to have those decisions quashed by the courts, Associated Provincial Picture Houses Ltd v Wednesbury Corporation (1948) 1 KB 223.

This principle applies to the Inland Revenue, since the commissioners owe a duty of fairness to each individual taxpayer.

It is not even necessary to prove an improper motive, since conduct which, in a private law case, would constitute a breach of contract or an estoppel can be treated as an abuse of power, R v Inland Revenue Commissioners ex p Preston (1985) AC 835 HL.

The procedure is set out in s 31 of the Supreme Court Act 1981 and RSC ord 53 and a stay of proceedings will normally follow a successful application for leave.The client becomes agitated at the mention of the possibility of two hearings in the High Court.

He has read about the fat cats and wants to know whether there is a cheaper option.

Arguably there is.

The normal rule is that public law rights cannot be relied on in an ordinary action, O'Reilly v Mackman (1983) 2 AC 237 HL.

However, the rule has, on occasions, been relaxed.

In Davy v Spelthorne BC (1984) AC 262 the House of Lords held that a plaintiff could claim damages from a planning authority for negligent advice.Of even greater similarity on the facts to the present case is Wandsworth LBC v Winder (1985) AC 461.

The defence disputed a claim for rent arrears on the basis that the council's procedures for increasing the rent were ultra vires.

The council applied to strike out the defence as an abuse of process but eventually the House of Lords held that it was not an abuse of process and that neither s 31 nor RSC ord 53 restricted the right of a private citizen in the course of defending an action to challenge a decision of a public authority.

On this basis, a defence pleading that the decision to continue the action was unreasonable should at least survive any application to strike out or for summary judgment.However, the end result is less certain.

Judicial review is only likely to be obtained against the Inland Revenue if the decision is shown to be an abuse of power, since their primary duty is to collect taxes, Lord Templeman in ex p Preston at 864.

Even although Mr Preston had reached an agreement as to his tax liability, the Revenue was held to be entitled to reopen the case.Similarly, the Revenue has escaped judicial review after resiling from agreements that dividends could be paid gross ex p MFK Underwriting Agencies Ltd (1990) 1 All ER 91 and when deciding to prosecute only two of a group of 50 evaders of tax, ex p Mead (1993) 1 All ER 772.

One of the few examples of success for the taxpayer is ex p Goodacre (1994) STC 799, when a refusal to grant leave to appeal out of time was quashed.

On this basis, the client may be in with a chance.Otherwise, success in practice may still depend on being able to show an improper motive.

Even in the context of the county court action, the judge could well conclude that, in tax cases, CCR ord 42 r 10 creates a special regime and that Winder is distinguishable on that basis.It is of such stuff that ombudsmen and human rights bills are born.

When the Human Rights Act 1998 comes into force, there may be a right to rely on the convention as a defence if the Revenue can be shown to be in breach of article 6.

Meanwhile the client can contact the Revenue adjudicator, who will give an independent recommendation but who has no power to stay the proceedings.

If all else fails, clients can complain to their MP, ironically a course recommended by the Inland Revenue in its leaflet on complaints.