Video report by ITV News Political Correspondent Paul Brand
Andrea Leadsom has told ITV News she has learned from her last failed Conservative leadership bid to be more focused and prepared after confirming she is "seriously considering" entering the race to replace Theresa May.
The leader of the House of Commons, who withdrew from the 2016 race with Mrs May after her comments on motherhood in a newspaper interview sparked controversy, suggested she will change her strategy for a second bid to run both her party and the country.
"I've been determined over the last three years to support the prime minister in getting her Brexit deal over the line. She has said that she is going to stand down and so yes I am seriously considering (standing for leader)," she told ITV News Political Correspondent Paul Brand.
Mrs Leadsom quit the last contest after telling The Times having children gave her a "very real stake" in Britain's future - in contrast to Mrs May, who was denied motherhood for health reasons.
Asked what she would do differently this time, she said: "You do know about the advantage of being prepared and thinking about it carefully, understanding exactly what it is you want to achieve.
"I withdrew for very good reasons that still hold true and I'm very supportive of the prime minister to deliver Brexit."
While several cabinet figures are expected to contest the Tory leadership battle, only International Development Secretary Rory Stewart has publicly declared his intention to stand.
More on the Tory leadership race:
Moves from senior Tory MPs to commit the PM to a road map to leave her post - and thus trigger the leadership race - come amid stumbling cross-party talks on Britain's departure from the EU.
On the latter, Mrs Leadsom warned against the government agreeing to Labour's demand for an exit deal that includes some kind of customs union.
Asked by Brand if she could stomach a customs union with the EU until 2022, she said: "What I wouldn't want to see is some kind of arrangement that meant we couldn't write our own free trade deals with the rest of the world, because the huge opportunities of Brexit, of which there are very many, lie in being able to trade freely with the rest of the world and develop those relationships more than we've been able to do as a member of the European Union.
"I would need to see exactly what the arrangement with Labour is, I'm not party to those discussions. I'm certainly concerned about us doing a deal with the Labour Party, it's not something that I would welcome, but the reality is we have to leave the European Union and we are in a hung parliament."
She accepted the stalemate in the Commons would force some sort of conciliation to win majority support in the Commons.
"If you haven't got the numbers you have to get them from somewhere, and that means compromise," she said.
"To get Brexit over the line, proper Brexit properly leaving the EU, we do need to look at all the possibilities."
Asked by Brand if she would personally advise Mrs May on when to leave office, Mrs Leadsom said: "The prime minister has made her decision clear, that she wants to get the Withdrawal Agreement bill through and that she will then decide on the time of her choosing to leave.
"And that is a matter for her, it's not something I would seek to get involved with."
Mrs Leadsom would also not be drawn on the factors she is weighing up before deciding whether to run again, only saying "making sure we leave the EU" remains her "absolute priority".
The Commons leader spoke as she warned Parliament could suffer a "catastrophic incident any day" before MPs leave in the mid-2020s to allow the £3.5 billion restoration work on the Palace of Westminster to begin.
Drawing comparison to the fire disaster that struck Notre Dame last month, she said: "Just the other day we had a big flood in the chamber. We've had 66 fire incidents since 2008. Just recently we've had three pieces of falling masonry, one of which could have really hurt someone. So there are all types of potential catastrophic failures.
"We've seen the asbestos everywhere. An asbestos leak would obviously be a catastrophic failure.
"The work that goes on day-to-day to keep us safe is absolutely focused on avoiding that happening but it is one of the risks that we face."
Mrs Leadsom, who entered the Commons in 2010, also rejected suggestions it would be more cost effective to permanently move the Houses of Parliament to a new location and turn the current Westminster site into a museum.
Watch: Andrea Leadsom gives Paul Brand a tour of Parliament's major flaws
"The Notre Dame is so much more than just a cathedral and likewise the Palace of Westminster is so much more than just a parliamentary building. It is one of the most famous sites in the entire world," she said.
"What we do want to do is preserve it for future generations. It's the heart of our democracy, it's a beacon of democracy around the world.
"What we need to do is give it the greatest chance ... to make sure it is a safe building for the next several hundred years."
She added: "This is a purpose-built parliamentary chamber. If we do move back in it's a living museum."