LABOUR need to “atone” for past mistakes if they want to win elections, according to a secret report leaked to the media.

The report, Emerging from the darkness, by long-serving Labour adviser Deborah Mattinson and her polling consultancy Britain Thinks, says the party lost last May’s election because Ed Miliband was seen as “weak and bumbling” and because voters still believe it was “in denial” about its “appalling” track record on the economy. In Scotland the party are seen as “incompetent” Tories who had let the country down.

The damning report was based on meetings with focus groups in June last year, before Jeremy Corbyn and Kezia Dugdale were elected. Members of the two Scottish groups in Glasgow and Edinburgh had all voted Labour in previous general elections before switching to the SNP last May.

Labour was told it needs to “take Scotland seriously”, with group members telling the pollsters that the party is now “firmly in the past”.

For the last few years, Scottish voters were angry with Labour feeling “let down and abandoned” – a feeling that came to a head during the referendum campaign.

“Labour lost interest in Scotland and took Scottish voters for granted,” the report says, “now anger has dissipated – Labour is just an irrelevance”.

The report goes on to say “Labour [are] indistinguishable from the Tories” but a “less competent, even laughable version”, and that the two parties have the “same aims, same policies, same politicians”.

Kezia Dugdale was regarded as a “nonentity” who was known “for a very anti-independence stance”. For the party to recover, Scottish Labour needs to show it understands why they’ve been rejected, the review said. They need to offer credible policy alternatives, especially in areas where the SNP is weakest.

The report also recommended the party should try to attract a “big” leader and consider “rebranding Scottish Labour as independent”.

Although primarily concerned with Labour there was good and bad in the report for the SNP.

Voting for them in May was a cause of “real excitement and pride” for voters who felt they were “part of an exciting change project”. To vote for them was “a defiant rebuff to those who had let them down.”

Nicola Sturgeon was seen as “one of us” by the groups, something the report says is incredibly rare for a politician. The party as a whole was seen as “totally in touch with the Scottish people from all classes”.

However, the report adds that the SNP is a “shallow brand” and complains that “there is confusion about what it can achieve.” It adds: “There is little concrete sense of what the SNP stands for, and some worry that they won’t prioritise effectively.” It goes on to say “Holyrood is basically irrelevant – with no sense that the SNP should be tested on their track record there”.

Obtained by ITV news, the review was commissioned by Harriet Harman when she was Labour’s interim leader between Miliband’s resignation and Corbyn’s election.

SNP MSP Linda Fabiani said the report should make Dugdale realise that she needs to “apologise for her and her party’s decision to stand shoulder to shoulder with the Tories during the referendum campaign”.