This was an appeal to the House of Lords in respect of the applicability of the doctrine of estoppel to guarantees, themselves governed by Section 4 of the Statute of Frauds 1677. Saint-Gobain had retained the First Defendant (“Inglen”) as the main contractor for the construction of a new factory in Yorkshire. Actionstrength was a labour-only subcontractor that supplied labour to Inglen. Inglen failed to make a payment to Actionstrength and Actionstrength indicated its intention to withdraw labour from the site. Saint-Gobain allegedly made an oral promise to Actionstrength that if Inglen did not pay any sums that were or became owing to Actionstrength, Saint-Gobain would make such payments directly to Actionstrength. Actionstrength claim payment from Saint-Gobain based on this alleged promise. This appeal does not concern the nature of the alleged promise, as it is accepted by the parties that the promise, if made, constitutes a guarantee to which Section 4 of the Statute of Fraud applies.
The question before the court was whether there was an estoppel that prevented Saint-Gobain from relying on the provisions of Section 4 of the Statute of Frauds.

Section 4 of the Statute of Frauds provides (to the extent that it remains in force):

“No action shall be brought … whereby to charge the Defendant upon any special promise to answer for the debt, default or miscarriages of another person … unless the agreement upon which such action shall be brought, or some memorandum or note thereof, shall be in writing, and signed by the party to be charged therewith, so some other person thereunto by him lawfully authorised.”

Actionstrength claimed that by reason of the alleged agreement between Actionstrength and Saint-Gobain as to payment, Saint-Gobain encouraged Actionstrength not to withdraw its labour from the site. Further, on the strength of that alleged promise, Actionstrength acted to its detriment in continuing to supply labour for the site. Finally, Actionstrength claimed that it would be unconscionable for Saint-Gobain to deny that it entered into a binding agreement as alleged.