Cleveland Bridge denies blackmailing Multiplex as chief executive recalls blazing row between respective owners.

The relationship between Multiplex and Cleveland Bridge on Wembley grew so bad it culminated in a blazing row between the rival owners of the firms, the High Court heard yesterday.

Revealing the extent of animosity between the main contractor and the steelwork specialist, former Cleveland Bridge chief executive Roddy Grant told the court of a "terrific screaming match" between Multiplex chairman John Roberts and Cleveland Bridge's major shareholder Sheikh Abdullah Al-Rusheid in February last year. Grant also revealed that Multiplex construction director Matt Stagg had accused him of attempting to blackmail the Australian firm over payment.

Under cross-examination from Multiplex QC Roger Stewart, Grant said Sheikh Abdullah and John Roberts had the row during a telephone conversation in February 2004. The dispute occurred as the companies were attempting to finalise the Heads of Agreement to provide a way forward on the project. Grant went on to describe the Sheikh as ‘a difficult chairman' to work for.

The court later heard that Matt Stagg had accused Grant of attempting to blackmail Multiplex in January 2004, after Grant implied that CBUK would face insolvency if it did not strike a revised deal with Multiplex. Stagg told Grant: "This is blackmail. The last person that did that to me [M&E contractor Matthew Hall] never worked in Australia again."

Under intense questioning, Grant admitted he had considered putting Multiplex under pressure by falsely claiming that the Sheikh had instructed CBUK not to lift Wembley's signature arch until payment disputes were resolved. However, Grant stressed that he had never actually made the claim to Multiplex.

Grant said: "These were potentially things I'd say if necessary in meetings… Something I might say in order to get attention. It wasn't the Sheikh's position. But I didn't say it."

The case continues.

For more from the High Court case on Tuesday, see Building this Friday.