Labour peer Baroness Shami Chakrabarti has offered an expansive list, covering everything from the weather to the media, to absolve Jeremy Corbyn of the party's trouncing in the Copeland byelection.

Corbyn faced renewed pressure to step down, or at least turn Labour's poor performance around, after the party lost the Cumbria seat for the first time since 1983 on the election on Thursday (23 February).

The Labour leader has remained defiant in his ambition to lead the party into the next general election and, appearing on the BBC'S The Andrew Marr Show on Sunday, Chakrabarti became the latest politician to say he was not to blame for Labour's troubles.

"Well I was in Copeland last weekend, knocking on doors," she said, "and I felt that Copeland is probably one of those constituencies that was neglected by my own party over some years.

"It's remote from London, it's changed its shape over many years, there's the nuclear industry and people have done very well out of that industry and then there's the people left behind.

"I think it just goes to show that you cannot weigh people's votes, you have to cherish them."

Chakrabarti also said an anti-establishment fervour was to blame, echoing comments made by Corbyn earlier in the week.

When asked to justify how an anti-establishment backlash would drive someone to vote for the Conservative Party and in favour of Prime Minister Theresa May, Chakrabarti said: "From my experience in Copeland, Labour has looked like the establishment for a very long time because they've [the constituency has] been represented by Labour for a long time."

She also said disunity within the party and the media focussing on the disunity, rather than Labour's message, was partly to blame.

Chakrabarti also took issue with Marr hosting Labour Peer Peter Mandelson in the run-up to the byelection, as opposed to someone within the Labour leadership and Corbyn's inner circle.

She was also forced to defend her comments that Storm Doris had deterred voters, when Marr said the UK has had rain and wind in byelections for hundreds of years and voters still managed to come out to vote against the government, which Labour was unable to attract voters to do.

In response, Chakrabarti said: "There was low turnout in Copeland. 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."

Trudy Harrison, of the Conservatives, won the byelection taking 13,748 votes – an increase of +8.46% over the party's votes in the 2015 general election. Labour's Gillian Troughton took 11,601, marking a -4.92% drop in votes for the party.

The latest UK polling report by ICM for the Guardian had Labour 18 points behind the Conservatives at 26 points to 44.