Interlocutory injunctions: american cyanamid comes of age

• Author: Jill Martin
• Position: Professor of Law, University of London (King's College)
• Pages: 76-95

INTERLOCUTORY INJUNCTIONS:

AMERICAN CYANAMID COMES OF AGE

JILL MARTIN*

In February 1975 the House of Lords delivered judgment in the

landmark decision, American Cyanamid Co. v. Ethicon

Ltd.,1

which

restated, or some would say revolutionised, the principles applicable

to the grant of interlocutory injunctions. Now that the House of Lords'

baby has reached the age of majority, it might be opportune to review

how the principles have worked, and in particular to consider the

growing number of exceptional cases where the American Cyanamid

principles have been held inapplicable. American Cyanamid altered the

previous practice by holding that a plaintiff seeking an interlocutory

injunction need no longer establish a prima facie case, but only that

there was a serious question to be tried, in which case the grant or

refusal of the injunction should be governed by the balance of

convenience. This review will concentrate on those areas in which it

has become apparent that the balance of convenience should not be the

governing factor, and that a just result can only be achieved by

requiring the plaintiff to establish at least a prima facie case, as under

the previous law.

The previous principles were stated in the House of Lords in

J.

T.

Stratford

& Son Ltd. v. Lindley:2 a plaintiff seeking an

interlocutory injunction "must establish a prima facie case" of some

breach of duty by the defendant to him. The point was not argued, but

this principle had been well settled for many years. It was only after

establishing

a

prima facie case, in other words that it was more likely

than not that the plaintiff would be successful at the trial, that other

matters such as the inadequacy of damages and the balance of

convenience came into play. Lord Denning, writing in The Closing

Chapter,3 put the matter thus: "But then in 1975 all our principles

Professor of Law, University of London (King's College). This article was

first presented as the subject-matter of the second Anthony Bland Memorial

Lecture given by the author at the Faculty of Law, University of the West

Indies, Cave Hill, Barbados, in February 1993.

1 [19751 A.C.396.

2 [1965] A.C. 269 at 338.

3 (1983), p.259.

were shattered and our experience overthrown by the judgment of the

House of Lords in American Cyanamid Co. v. Ethicon Ltd."

The new principles laid down by Lord Diplock in American

Cyanamid were, briefly, as follows: (i) the court must be satisfied that

the plaintiff's case is not frivolous or vexatious and that there is a

serious question to be tried; (ii) if so, the governing consideration is

the balance of convenience; (iii) a significant factor in assessing the

balance of convenience is the inadequacy of damages to each party;

(iv) if the balance of convenience does not clearly favour either party,

the preservation of the status quo will be decisive; (v) only as a last

resort should the relative strength of each party's case be taken into

account in tipping the balance; (vii) finally, "other special factors" may

have to be considered in individual cases.

The members of the House of Lords unanimously agreed with Lord

Diplock's view that there was no rule requiring the plaintiff to establish

a prima facie case. The new formulation was "designed to circumvent

the necessity of deciding disputed facts or determining points of law

without hearing sufficient argument."4 The view was that the court's

discretion would be unduly fettered if the injunction could only be

granted if the plaintiff could show that he was more than 50 per cent

likely to succeed at the trial, bearing in mind that difficult points of

law and conflicts of evidence, which was incomplete and untested by

cross-examination, could not be resolved at the interlocutory stage.

Interestingly, only a few months before American Cyanamid there

was another leading case on interlocutory injunctions, Hoffman-La

Roche (F.) & Co. v. Secretary of State for Trade and Industry,5 where

Lord Diplock

himself,

after reviewing the history of the remedy, had

said that the plaintiff had to show "a strong prima facie case that he

will be entitled to a final order." Neither this case nor Stratford was

referred to in American Cyanamid.

4 Smith v. Inner London Education Authority [1978] 1 All E.R. 411 at 426.

There may, however, be some cases where it would be appropriate to

resolve questions of law at the interlocutory stage: Associated

British

Ports

v.

T.G.W.U.

[1989] 1 W.L.R. 939 at 979, 980; R. v. Secretary for

Transport, ex p. Factortame [1991] A.C. 603 at 677.

5 [1975] A.C. 295 at 360.