Lord Kirkham has tabled a £496m, 445p-a-share offer, but institutional investors are said to be unhappy with this offer, the Evening Standard reported.
The independent non-execs, lead by Halifax chief executive Mike Blackburn, want investors to accept the deal, and have said they will have to reconsider their positions if the bid is rejected.
Investors will vote on the proposal at an extraordinary meeting scheduled for 7 September.
The other non-execs are former Iceland chief executive and founder Malcolm Walker and Kevin Morley, former Rover Car Group managing director.
Does Darwin's theory apply to taxation? Colin ponders...
The EC has been instructed to draft a European Union (EU) directive authorising an EU financial transaction tax, which would apply to ten of the EU’s 28 member states
Accountancy watchdog the FRC has dropped its investigation into the former chief financial officer of Tesco, nearly two years after the supermarket was engulfed in an accounting scandal
Colin imagines how Apple's logo might change in the wake of the EC's ruling over its Irish tax arrangements