P (hotel) was supplied with fuel by E. Ds (various union members, including fuel delivery drivers) put P under a fuel embargo. There was a force majeure clause in the contract between P and E saying that neither would be liable if the contract wasn’t fulfilled due to labour disputes. However Ds were still made liable for interference with the performance of the contract by CA on the grounds that union leaders shouldn’t be able to take advantage of the force majeure clause in the contract between P and E.
Lord Denning MR: The principle of interference with the contract should be extended to cover cases where the interference doesn’t cause any breach (as here)
Russell LJ (majority approach): There still has to be breach of the contract to bring a claim for tortious interference. However the force majeure clause is to be viewed as an exemption from liability for breach, and NOT preventing breach itself if there is a failure to deliver/take delivery of fuel.