The issue of the report, from Energy Resource Consultants, will represent Clyde's final card in its battle to fend off a hostile pounds 432m bid from rival Gulf Canada.
The end of Clyde's defence will turn the spotlight on Gulf, which has so far failed to persuade institutions of the merits of its existing 105p offer. Clyde's shares closed at the end of last week at 119p, suggesting the market expected a higher offer, and a number of institutions have indicated they would be unwilling to accept less than 135p for their shares.
Gulf has tried to talk down expectations that it will return with a significantly higher offer. Seen as a bid to talk down Clyde's share price, Gulf's stance has remained unchanged - it says it will walk away rather than overpay for Clyde. Despite its hardline approach, many in the City expect Gulf to return with a sweetened deal.