As the election results rolled in last Friday morning, two things were immediately clear for watching Liberal Democrats. It was a crushing disappointment. But it was hardly a new experience. As one senior figure put it: “We’re the Lib Dems, we’re used to having to pick ourselves up and rebuild after disasters. It’s what we do.”

Following a campaign buffeted by stagnant polling and disquiet over tactics, the party ended up with 11 seats, one fewer than it picked up in the 2017 election, and 10 fewer than it had before the poll, when its numbers were swelled by defections from other parties.

None of the new arrivals who stood again were re-elected and, more demoralising still, the party leader, Jo Swinson, lost her East Dunbartonshire seat to the SNP by 149 votes. Of the 21 pre-election contingent, only seven are still MPs, with three newcomers and one returnee – Sarah Olney in Richmond Park.

While this was only the second-worst performance in the Lib Dems’ 31-year modern history – in 2015 the party led by Nick Clegg slumped from 57 seats to eight – there is an argument that the letdown this time was even greater.

Facebook Twitter Pinterest Former Labour MP Luciana Berger fell short for the Lib Dems at the election in Finchley and Golders Green. Photograph: Jacob King/PA

Clegg and his MPs were braced for an electoral kicking after their coalition with the Conservatives. In contrast, three months before the 2019 election, the Lib Dems’ autumn conference was awash with bullish predictions of winning 40 seats as a minimum, with 80 or even 100 possible. Buoyed by strong results in the local and European elections in May, and polling numbers that briefly exceeded 20%, the party entered the campaign with ambitions that were arguably not matched by sufficiently rigorous organisation or on-the-ground campaigning.

Swinson faced criticism for an overly presidential approach, an initial pitch to the public as a prime minister-in-waiting, and the policy to revoke Brexit without a second referendum.Some within the party say the revoke idea was sprung on the party by Swinson and her team at the autumn conference. As the flagship policy of a newly elected leader, they say, it could not realistically be refused, despite doubts among some senior members.

“People understood the revoke idea if you explained it on the doorstep,” one candidate said. “But it’s like Labour on Brexit – it’s better to have a policy that doesn’t need explaining in the first place. People understood the people’s vote.”

Another candidate said: “There’s no doubt it was a mistake. But also, there’s no data that backs up what people are saying about it costing us votes.”

For now, a sprinkling of gallows humour helps with the coping process. “The good thing about not winning so many seats is it’s going to be pretty easy to get to know all the parliamentary party,” one MP said.

Serious, even potentially existential challenges loom as the process of choosing a new leader begins, not least deciding the raison d’etre for a party that went into the election so closely defined by one, now largely defunct idea – remaining in the EU. Other key challenges include how to avoid the Lib Dem vote being squeezed yet again under a first past the post electoral system, escaping the legacy of the 2010-15 coalition, and improving party organisation.

These questions will go hand-in-hand with the leadership race, the timetable for which has yet to be decided by the party’s ruling federal board. One mooted option is to make the decision before the spring conference in York in mid-March.

But with a battle-hardened interim leadership team of Ed Davey, Swinson’s former deputy, and the Lib Dem peer and president, Sal Brinton, already in place, others are arguing for a longer process, one where the party membership – at a record 120,000-plus – could potentially make their decision in the light of Labour’s new leader. Some even suggest keeping Davey in place for a year or more.

A paradoxical advantage of the election result is that the field to replace Swinson is not exactly crowded. As one senior member put it: “If you take away the new MPs, and the ones who probably don’t want it – Tim Farron, Alistair Carmichael and Jamie Stone – that leaves four people.”

Facebook Twitter Pinterest Layla Moran, regarded as a leadership frontrunner. Photograph: Wiktor Szymanowicz/Barcroft Media

Of those, Davey and Layla Moran, the latter returned to her Oxford West and Abingdon constituency with a notably increased majority, are seen as the frontrunners, even though it is understood that Moran has yet to decide whether she will stand. Also in the frame are the Bath MP, Wera Hobhouse, and Christine Jardine in Edinburgh West, both 2017 entrants, as well as the brand new MP Daisy Cooper, who took St Albans from the Conservatives and has not ruled out a leadership bid.

Davey, an MP since 1997 and a cabinet minister in the coalition, is seen by some senior Lib Dems as the safe, if perhaps shorter-term choice. “This is a time for experience and good judgment,” one Lib Dem figure said. “It can be hard to run a party, especially when the party is at a low ebb.”

Others see Moran, a confident media performer who, at 37, is two years younger than Swinson, as the better option. “If she goes for it, you could say the leadership is hers to lose,” a Lib Dem source said. “Ed doesn’t really answer the big questions the party has got to answer. And under Layla we could finally stop having to talk about the coalition.”

Before the new leader is chosen comes a more immediate task: a formal postmortem into what went wrong with the 2019 election.

It is a worry that too much emphasis was placed at the election on winning London seats for high-profile incomers from other parties, such as ex-Labour MPs Luciana Berger and Chuka Umunna, both of whom achieved significant swings but fell short. “I think maybe some people believed that if we focused on those we’d just pick up other seats along the way,” one party figure said. “But it doesn’t work like that. In retrospect, it might have been better to focus on a core strategy of something like 20 seats, go for at least some gains.”

At the same time, at least some of the newcomers from other parties are understood to have been surprised at the lack of non-Brexit policy direction ahead of the election, even if some of this was down to the fact Swinson took over as leader only in July.

Perhaps most relevant to the eventual result was another insight gained by some of the defectors as they fought their first election within the new party: life as a Lib Dem is a difficult business even at the best of times.

“It’s not just the electoral system, or the lack of resources, there’s also the media,” recounted one new arrival. “You have to work 10 times as hard to get any cut-through. About 50% of any interviews I had were spent on questions about who we would or wouldn’t prop up in government. That doesn’t leave much time to talk about policies.”