Both men won the support of 2,000 party members at a hustings meeting only hours after Mr Norris played down remarks that he would not support the best-selling novelist "dead or alive". The former transport minister claimed the attack had been "throw away comments during a light hearted conversation".
But Lord Archer fought back during his speech. He said: "If you should decide to support someone else let me make one thing clear - in great Conservative tradition - I will support that person 100 per cent."
Mr Norris's comments were made during a conversation with the former Tory MP Richard Tracey at a Conservative Party function three weeks ago. He said: "I tell you something. I will never, ever support Archer, alive or dead," and did not realise he was wearing a BBC radio microphone at the time.
He told Greater London Radio initially that he did not making the comments, but in an embarrassing climbdown Mr Norris later accepted that he had, but he dismissed its seriousness.
The two men beat two other hopefuls, Andrew Boff, the former leader of Hillingdon Council and Bob Blackman, the leader of the Tories on Brent Council, at the hustings.
The "two-man race" will now be decided by a postal ballot of the 38,000 members of the Conservative Party in London. The final result will be announced on 1 October.
Both declared after the result that a Conservative candidate was needed to address London's problems.
Lord Archer caused controversy recently with comments about the dress sense of Afro-Caribbean women, but his candidacy recovered after an endorsement by Baroness Thatcher. In a final pitch for support, Lord Archer told party members: "If you are only going to have a saint for this job, I'm certainly not your man. But if you want somebody with energy and ideas I would like to take that challenge."
Mr Norris is also confident of his chances after his last-minute decision to marry his mistress and mother of his 18-month-old son.
He said last night: "My strengths for this job are my commitment and competence - my prudent competence."
A Tory spokesman declined to give the exact result of the secret ballot. He said: "Both Steve Norris and Lord Archer have shown to be outstanding candidates for London Mayor. "It is now up to London members to decide democratically - one member, one vote - who will compete for the job next May. That is more than could ever be said about the selection process in the Labour Party which seems to be obsessed with stopping Ken Livingstone."
The Labour Party's nomination for their official candidate is not expected to be announced until later this year and Downing Street is known to be determined to stop Mr Livingstone - former left-wing leader of the Greater London Council before it was abolished in the 1980s - from standing.
Glenda Jackson and Tony Banks have already announced that they will seek to get the job but senior party sources still hope that Frank Dobson, the Health Secretary, can be persuaded to stand.Reuse content