The Liberal Democrats have elected Brian Paddick as the party's candidate for the London mayoral election.
The 53-year-old former Police Commander, who came third in the 2008 election, is to be unveiled on Monday morning.
Following confirmation of his candidacy, Paddick said: "I want to thank my fellow candidates for engaging in a high standard of debate throughout the campaign.
"I also want to thank my excellent team without whom I would not have been selected.
"Most of all, I want to thank London Liberal Democrat members who placed their trust and confidence in me to be their candidate for Mayor of London - I won't let you down."
Commenting on Paddick's election, Deputy Prime Minister Nick Clegg said:
"Brian's experience is exactly what London needs right now. Whether dealing with the aftermath of the riots or phone hacking and corruption in the Metropolitan Police, Brian has shown in recent weeks that he has the authority and leadership that London needs.
"Brian provides Londoners with a real, credible alternative to Boris Johnson and Ken Livingstone."
Paddick's confirmation means the same line up that contested the 2008 election will appear on the ballot paper in 2012.