The electoral bloodbath which saw the Liberal Democrats reduced to just eight MPs was a "perfect storm" with the party hit by poor morale, an effective Tory strategy and public anger over the tuition fees U-turn, an internal report has concluded.
The review of the general election found there was confusion over key campaign messages and then-leader Nick Clegg had been unable to repeat the success of his 2010 TV debate performances.
Mr Clegg resigned in the wake of the drubbing the party received in May 2015, but the review concluded that the electoral fight was "always going to prove difficult" for the party following its decision to join the coalition government with the Tories.
The review, by the Lib Dems' campaigns and communications committee, concluded: "The loss of some of our longest-held seats, and with them our most experienced and nationally acclaimed MPs, is the culmination of a perfect storm sweeping them away on a wave of Tory message and money, a weak Labour Party, an anti-Westminster SNP campaign that built on the Scottish referendum, a misdirected public perception of proximity between the Labour and Conservative parties, a hollowed-out Liberal Democrat activist base and general disengagement as a consequence of policy decisions such as tuition fees."
The U-turn on tuition fees "significantly damaged our reputation and credibility" and it was "almost incomprehensible" that the party had ended up in a position where 27 of its MPs - including Mr Clegg and other senior figures - had voted to triple fees as part of a package negotiated by a Lib Dem cabinet minister, Sir Vince Cable.
The document was highly critical of the campaign approach adopted by the Lib Dems, saying the move into government was "not well understood" and there was "weak public understanding" of the party.
"This was only exacerbated by the nature of running hyper-local campaigns with differing messages in different parts of the country," the report noted.
Coupled with a lack of money compared with Labour and the Tories, by late 2010 - just months after entering government - there was a "daily reality for the party of public rejection, falling internal morale and consistent electoral destruction".
The party carried out "no polling activities of note" in the first two years in office - partly due to dwindling funds - meaning that "those making decisions were effectively flying blind".
The Lib Dems won 57 seats in 2010 and benefited from "Cleggmania" following the leader's strong performance in the TV debates, but were almost wiped out in 2015.
"It was always going to be difficult for Nick Clegg to achieve anything like the cut-through of 2010, though our members and media made clear at the time that they thought his performance was strong," the report said.
Responding to the review, Lib Dem leader Tim Farron said: "It is a credit to our party that we can take such a long, hard look in the mirror.
"To me, this review is about setting a blueprint for our future. It is from this moment we can set ourselves a clear vision for rebuilding, and creating the election-winning force we know we can be.
"Blame and criticism can provide short-term satisfaction, but do nothing for a future vision. This report is about setting a way forward, recognising the mistakes we made, and learning from them.
"We must also remember that many dedicated, passionate and committed Liberal Democrats worked tirelessly throughout the campaign. There were many great things we did together, and we should not allow the dark cloud of the result to completely encompass the many good things that happened."