Oftel handed out the new six-digit DQ numbers starting '118' in a draw to around 80 applicants last Tuesday.
Having failed to draw an easily memorised number, BT has offered to buy the more memorable 118118 number from business carrier Leaf Telecom, which drew the number in last week's lottery.
Telegate, one of Europe's biggest DQ companies set to enter the UK market, is this week writing to Oftel director-general David Edmonds and alerting MPs to prevent applicants selling their numbers to the highest bidder.
Oftel has said it cannot intervene in events after the draw.
The numbers come into effect in October with the existing 192 service phased out in August 2003. Deregulation will enable consumers to dial whichever DQ provider they choose, regardless of their phone network.