After Mr Cable announced he will leave his post, bookies make Jo Swinson the even money favourite to replace Sir Vince at the helm of the party.
Jessica Bridge of Ladbrokes said: “As and when Sir Vince decides to stand down, the odds suggest it’s a two-horse race between Swinson and Moran for the top job.”
But Ed Davey and Remainer Ms Miller are also considered among the favourites, with their odds respectively at 6/1 and 10/1.
However, Mr Cable, 75, said he won’t immediately quit his role, but will leave only after the announced new party’s structures are implemented and Brexit “is resolved or stopped”.
He told the audience at the Liberal Club in London: “Now is not the time for an internal election, once Brexit is resolved or stopped, that will be the time to conduct a leadership election under the new rules.”
Britain is set to leave the European Union on March 29 2019.
But Remain-backing Lib Dem party leader is actively working against the withdrawal, advocating with his party for a second referendum.
Explaining he will lead the Lib Dem through Brexit and any other general election coming next year, Mr Cable said: “Reports I have read of my imminent departure are very wide of the mark.
“Now is not the time for an internal election, once Brexit is resolved or stopped, that will be the time to conduct a leadership election under the new rules.”
Calling directly at Labour and Conservative MPs unhappy with their parties’ positions, the head of the Lib Dem said: “I make the case that it is much easier under our electoral system to work within existing party structures and with people who have shared values, rather than trying to compete.
“As the old adage has it: we hang together, or we hang separately.”
The Lib Dem chief also set out a plan to attract younger voters and more Remain supporters.
He said: “We should widen membership with a new class of ‘supporters’ who pay nothing to sign up to the party’s values.”
He also said voters who are “liberal-minded” should be allowed to sign up for free under plans to bolster membership.
He explained: “We should widen membership with a new class of ‘supporters’ who pay nothing to sign up to the party’s values.”
The Lib Dems have been struggling electorally since they joined the government coalition with the Conservatives in 2010.
Mr Cable added he wanted to create a “movement of the moderates” that would bring together voters who loosely identify with the party.
Mr Cable’s announcement comes as a senior Lib Dem revealed the party is working to form a centrist alliance with Remain-backing and moderate Tory and Labour MPs.
Speaking to Business Insider, the anonymous source said Mr Cable is looking for people interested in defying their party whips.
The new group won’t be a proper party in its early stage, but rather a coalition coming together on important issues, the source continued.
Among those deemed interested to split from their party whips are two Labour MPs, Chuka Umunna and Chris Leslie, and Conservative backbencher Anna Soubry, they claimed.
The party will meet next week for its annual conference in Brighton.
Mr Cable, MP for Twickenham, was appointed leader of the party in 2017, when no other viable candidate came forward on the ballot after Tim Farron quit.