The database is called the Postcode Address File, and contains the 24 million address details of everyone in the UK.
Everyone from marketing firms to the emergency services pay a fee to access the file, which is run at arms length by Royal Mail, to ensure addresses are kept up to date.
Cabinet Office minister Francis Maude has been privately battling with Business minister Michael Fallon over whether to include the database, worth between £500million and £900million, in Royal Mail's flotation, which is expected as early as October.
Last month Sir Tim entered the debate on Mr Maude's side, writing to the Prime Minister urging him not to sell it off and instead open it up to more small firms to access. One idea was to spin it off into a John Lewis-style mutual structure.
Mr Maude had argued that the database "actually has much more worth for entrepreneurship and the overall growth, agenda" if it was run as a mutual and owned by people who used it.