Labour MPs have expressed anger after Jeremy Corbyn decided not to attend a weekly meeting used to dissect the party’s historic loss in Copeland last week, with one accusing the party leader of a “total dereliction of duty”.

Frustration was also vented by one MP at the meeting after an image emerged, reportedly showing two of Mr Corbyn’s allies – Diane Abbott and Shami Chakrabarti – enjoying a beverage in Westminster while the meeting was underway.

Andrew Gwynne, who led the party’s campaign in Copeland, and Ian Lavery, a shadow Cabinet minister, led the postmortem discussions on the Copeland by-election while Jack Dromey, a Labour MP who helped run the successful defence of the party’s Stoke-on-Trent Central seat, appeared alongside.

Mr Corbyn did attend last week’s session, telling his parliamentary colleagues that the by-election in Copeland was on a “knife edge”. But on Thursday the party suffered a historic loss in the Cumbrian seat – the first time a governing party has won a seat off an opposition since the early 1980’s.

One MP, who was present at the meeting, told The Independent that Mr Corbyn’s absence was a “total dereliction of duty”. They added: “Poor old Andrew Gwynne can’t account for everything that was raised on his own”.

Another added that they “couldn’t understand why the leader didn’t attend”.

A Labour source, however, told journalists outside the PLP that Mr Corbyn offered his apologies for being unable to attend the session and pointed out that he doesn’t attend every week.

Labour's Shami Chakrabarti blames range of factors- except the party's leader- for Copeland loss

On the image of Ms Abbott and Baroness Chakrabarti, Graham Jones, the MP for Haslingden and Hyndburn, said: "It's disappointing that it appears Shami and Diane are in the Pugin Room. Shami had a lot to say at the weekend, it's a shame she didn't have a lot to say in the meeting.

"Perhaps if she had turned up she could have explained her comments. When it was revealed where she was, people felt it wasn't in order.

"There's a degree of frustration because she's not elected and she speaks like someone who is elected. She has no authority from any electorate and people feel there's a disconnect and those of us who have the views of voters to take on board and consider."

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Speaking at the Scottish Labour Party conference in Perth at the weekend, Mr Corbyn said he took his “share” of the responsibility for the defeat and conceded that the party had not yet done enough to rebuild trust with disillusioned voters.

But with his critics demanding a change, either in leadership or strategy, anger spilled over when Baroness Chakrabarti gave an interview suggesting Copeland could in-part be explained by other factors including bad weather, Labour voters being less likely to have a car, low turnout, Brexit divisions, false claims about Mr Corbyn’s views on nuclear power, and ill-treatment in the media.

According to some of those present at the meeting, Labour MP Lilian Greenwood read out a long list of reasons provided for the party’s loss in Copeland, before asking: “Is there anything missing from the list?”