The move comes after the new iPhone 4 was beset by complaints since its June launch, which claim reception can be affected by the way the handset is held.
This week influential US buyers guide Consumer Reports dealt Apple a blow by saying it could not recommend the phone because of the antenna problems.
The company sold 1.7 million iPhone 4 handsets in the countries where the phone is available (the US, UK, France, Germany and Japan) in the first three days, so should tomorrow’s press announcement include even a partial recall of the product it would create a logistical and public relations disaster for the firm.
Reports suggest that what could possibly stop customer dissent is a free offer of the iPhone 4 rubber bumper case, which would solve the reception problems by creating a barrier between a user’s hand and the antennae.
However, neither has yet been sanctioned by Apple and the company has refused to reveal any details about the conference, which will take place at 6pm UK time.
In the UK the launch was met with anticipation as people queued for up to 48 hours to be the first to get their hands on the phone.
Up to 1,000 people queued outside the flagship Apple store in Regent Street before door opened at 7am.
Apple claimed its display and larger battery gives the phone 40% more talk time that the previous 3GS model and users will be able to browse a 3G network for up to six hours before recharging.
These claims were, however, overshadowed by the reception issue and criticisms of the phone's performance surfaced within hours on tech blogs around the world.
In a letter to iPhone 4 customers earlier this month, the company said: "For those who have had concerns, we apologize for any anxiety we may have caused."