The Scottish Labour leader warned the party’s divisions were turning off voters and said long and hard thinking had to be done to turn round its fortunes.
Asked about the by-election which saw a once-safe Labour seat fall to the Tories, Ms Dugdale refrained from criticising Mr Corbyn directly.
But she said: “Divided parties are not appealing to the electorate and given that I am at this conference here in Perth under a banner of `Together We’re Stronger’, I’m in no business of being critical about anyone. But there is clearly a collective failing of Labour to put its platform in Copeland.”
Questions about Mr Corbyn dominated Ms Dugdale’s appearance at a Daily Record sponsored fringe meeting at Scottish Labour’s spring gathering in Perth.
Ms Dugdale said: “I recognise this is a collective failing on behalf of the party to win the support and the trust of people in the North of England.
“Am I worried about that? Of course I am, because I want to a Labour Prime Minister and a UK Labour Government. It is what I came into politics to strive for. I joined the Labour Party in 2003 exactly because there was a Labour Government which was transforming the life chances of people throughout this country.”
She added: “I want them to do that again and I want Theresa May very firmly out of office. There’s a lot of long and hard thinking that needs to be done but it has to be done by more than one person.”
She added: “There’s undoubtedly a reality which is a party that’s been fighting itself for a year and has been seen doing just that in the eyes of the public. [The party] has to do a lot more to make it look like the united force and it needs to be to look like an alternative government.”