The odds come despite the release of a YouGov poll for the Times last night suggesting that just 31% of Conservative party members would back Leadsom for the leadership, compared with a massive 63% who would vote for Theresa May.
But both are still way ahead of the other candidates, with third-placed Michael Gove managing just 8% in the poll.
Leadsom's improved odds are almost certainly down to an endorsement by Boris Johnson, who announced his backing on Facebook on Monday. He said that "Andrea Leadsom offers the zap, the drive, and the determination essential for the next leader of this country."
His endorsement of Leadsom may come as a surprise to some, but Johnson - who was the face of the Vote Leave movement in the EU referendum - was perhaps left with little choice given Gove's leadership campaign curtailed his own and May had backed Remain.
With Leadsom now the focal point of the Conservative right - as well as the
Here is a breakdown of the top three contenders' odds from the major bookmakers:
- Ladbrokes: May 4/11 - Leadsom 5/2 - Gove 16/1
- William Hill: May 4/9 - Leadsom 2/1 - Gove 16/9
- Betfair: May 4/11 - Leadsom 5/2- Gove - 14/1
- Paddy Power: May 2/5 - Leadsom 9/4 - Gove - 14/1
- Sky Bet: May 1/3 - Leadsom 5/2 - Gove - 18/1
The first round of Tory leader voting among MPs will take place today. All 330 party MPs will vote, with the weakest candidates eliminated before another set of votes set to take place on Thursday and the following Tuesday.