Sir Vince Cable looks set to become Liberal Democrat leader after all of the party's senior MPs ruled themselves out of the race to succeed Tim Farron.
Nominations for the contest close on July 20 but after former cabinet minister Sir Ed Davey said he would not run, Sir Vince appeared to be on course for a coronation as the only declared candidate.
The leadership contest is open to all 12 Lib Dem MPs, who must secure the support of two colleagues in order to stand.
But other potential candidates, including deputy leader Jo Swinson, chief whip Alistair Carmichael, Brexit spokesman Tom Brake, health spokesman Norman Lamb and work and pensions spokesman Stephen Lloyd have ruled themselves out.
A senior Lib Dem source said they would be "surprised" if any of the other MPs, Wera Hobhouse, Jamie Stone, Christine Jardine and Layla Moran, stood for the leadership, given that they only entered the Commons this month.
The leadership battle comes after Mr Farron announced he would quit because he had been unable to reconcile his Christian faith with the demands of leading a "progressive, liberal" party.
Writing on the Liberal Democrat Voice website, Sir Ed said his decision came after a camping trip with wife Emily and children John and Ellie.
"I've come back to Westminster more determined than ever to campaign hard for the party Emily and I both love, but not to campaign to lead the party at this moment," he said.
Setting out the personal reasons behind his decision, the Lib Dem home affairs spokesman said: "Our joy this weekend was seeing our two children play together.
"And when you understand that John (aged nine) is severely disabled, you will appreciate that seeing our three-year-old daughter make him laugh is quite special.
"And if it helps explain my decision not to run just a little more, please remember that my father died when I was four and my mother when I was 15.
"Being there for my children over the next few crucial years and to see those special moments is my personal priority.
"So my decision not to stand now to be leader of our party is a difficult one, but it is rooted in my family: the need to be there for my young children and not continually away from home; the need to protect my family from the inevitable intrusion on our lives; and the need to protect myself from pressures that would otherwise compromise my job as a father while they are still so young.
"And this was a difficult decision, because I want to play a big part in rebuilding our party, and taking it into power, at all levels of government.
"If I'd run, my message would have been simple: we need to be the party of reform, challenging the status quo.
"Saying the uncomfortable things. Recognising how broken our politics is."
He said the Lib Dems had to be "super ambitious", drawing inspiration from Emmanuel Macron's success in France.
Reacting to the news, Sir Vince tweeted: "Very much admire & respect what my friend & colleague @EdwardJDavey has said today on Lib Dem Voice about the importance of family."