My landlord has said they will not consult under Section 20 as the works are urgent. Is this correct

The landlord has  a legal obligation to consult for major works. There is an exception to this rule when the landlord makes an application to the Tribunal to dispense with the need to consult.

The Tribunal can dispense with the consultation requirements in a particular case if satisfied that it is reasonable to do so. For example where very urgent works are required (on the grounds of safety etc) or it is difficult to obtain more than one estimate.

Clarification as to what is required to be shown before the court or the Tribunal can grant dispensation, was provided in this case.

You may require the services of a solicitor.