Shadow cabinet member Shami Chakrabarti was mocked on Sunday after blaming Labour’s disastrous Copeland by-election defeat on everything from bad weather to poor public transport... but not Jeremy Corbyn.

Baroness Chakrabarti also suggested explanations could include Labour voters being less likely to have a car, low turnout, Brexit divisions, false claims about Mr Corbyn’s views on nuclear power, party disunity and ill-treatment in the media.

Following the interview on the BBC’s Andrew Marr Show, one Labour MP ridiculed the “pearls of wisdom from the never-having-stood-for-election ... wing of the Labour party”.

It comes amid pressure on Mr Corbyn to consider his position in the wake of the defeat, which was the first time an opposition party was defeated by a governing party in decades.

Challenged over claims that Labour’s vote may have been hit by Storm Doris, particularly given Labour voters are less likely to have cars, she said: “That is one aspect of all by-elections.”

She went on: “There was a low turnout in Copeland and having been to Copeland recently, I know that it’s a very rural constituency, public transport is not great. But it’s just one factor, of course that’s not the entire explanation.”

The Baroness explained that Labour had neglected voters for many years in Copeland, but also turned on party disunity, claiming that constant speculation over the leadership and infighting had damaged Labour’s “cut through”.

Her comments echoed claims by shadow Chancellor John McDonnell, who attacked Tony Blair and Peter Mandelson for making high-profile interventions shortly before the by-elections in Copeland and Stoke-on-Trent Central, which Labour won.

John McDonnell shifts blame on to Tony Blair and Peter Mandelson after Labour Copeland by-election defeat

She then went on: “Sometimes we haven’t had the fairest or most balanced treatment in the media, including in the broadcast media.”

Challenged by Mr Marr as to why the left “always blames the media”, she added: “I’m not blaming the media. I’m just saying that the disunity has been the focus.”

Labour insiders had feared that Mr Corbyn’s long-held views opposing nuclear power may also damage the party in Copeland, where the nuclear industry is a major employer.

Mr Corbyn attempted to mitigate the impact by insisting during the campaign that he is right behind development of the nuclear industry in the constituency.

Conservatives take Copeland in humiliating blow to Labour

However, Baroness Chakrabarti, who joined Labour under Mr Corbyn, said: “There are peculiarities about that seat, like what was said about our position on the nuclear industry which was apocryphal.

“But I don’t want to just make it all about the specifics of Copeland. We’ve clearly got work to do, we’ve clearly suffered from disunity – two leadership elections in the space of a year. We’ve clearly suffered from the fact that out supporters were divided, like the country over Brexit, and that’s been such a big issue.

“But now I think once Article 50 is triggered, as it will be, we have an opportunity to unite about things that clearly matter to people’s lives, like schools and hospitals and benefits.”