Leader of the Lib Dems Jo Swinson has argued a vote of no confidence during Tory party conference would play into Boris Johnson’s hands.
The opposition parties have agreed not to press ahead with the plan while the leaders disagree over who should become the next prime minister.
Speaking to journalists outside parliament, Swinson said: “It is positive that the cross-party discussions that are being had continue to be constructive.
“What is clear is that this week it is important we don’t go for a precipitous vote of no confidence motion.
“It is understood that, if anything, that would just increase the risk of a no-deal Brexit and therefore play in Boris Johnson’s hands.
“What is going to happen is the party whips are going to meet to plan out different scenarios and different options, including the possibility of an insurance option of a government of national unity, including who might be able to lead such a government.”
Swinson held strong to her oft-proclaimed vow that Corbyn would not enter Downing Street propped up by the Lib Dems.
The former coalition minister said: “I have been crystal clear but I will do so again – Jeremy Corbyn is not going into Number 10 on the basis of Liberal Democrats votes.
“In terms of a government of national unity, it is just not a runner (for him to be leader) – look at the arithmetic.
“One of the first rules of politics is being able to count and count votes.
“Whether it is the 21 rebel Conservatives or whether it is the members of Change UK, whether it is former MPs who left the Labour Party not least because of Jeremy Corbyn’s position on anti-Semitism, he simply doesn’t have the numbers.”
The Labour leader has insisted that he, as leader of the opposition, should take over if Boris Johnson is toppled by a vote of no confidence.
In an interview on Monday, Corbyn said: “The position is quite simply this: when a Government collapses then the leader of the opposition is invited to form an administration.”